Friday, October 29

This Friday we got our Unit 3 tests and our first quarter grades. We went over the test and then Mr. Henderson explained to us that the computer took off three of our worst webassign homework grades. There seemed to have been a problem, so he said that he would fix it once we went to the science computer lab. Once we got into the science computer lab we had to get with our qroups and exchange our information and work for the flight crash problems. Mr. Henderson said that if groups finished early they could start on the homework which was a Chemthink on chemical reactions. First we had to look at the tutorial to get the idea of the subject. Then we had to take a quiz on the material we just learned. You could only get 2 wrong. If you got three wrong you had to start over. mr. Henderson also told us a bout a work sheet on the back of the new packet that would be due with the Chemthink. The page has a front and a back side to it. An easy way to get it done would be, going through the tutorial and writing in the answers as you follow.

The basics of what we will be learning about in this unit is that the starting materials are called reactants, the materials that are created are called the products. You know that there has been a change when there is an arrow in between the two. This is just a little from the chemthink. There is a lot more to it than this. But I will let you figure that out for yourself.

Thursday, October 28

Thursday was test day. We took the Unit 3 test with 15 multiple choice questions, a page of short calculations and a page of longer calculations.  This day marks the official end of Unit 3.

Unit 4 will begin on Friday. Unit 4 is concerned with the topic of chemical reactions. We will learn what a chemical reaction involves and how different reactions can be characterized based upon their features. We will also learn how to use atom counting as a means of balancing chemical equations via the trial and error method. The unit will end as we focus upon precipitation reactions and learn to predict what precipitate will form as two aqueous solutions of ionic compounds are mixed. There will be virtually no mathematics in this unit. There will be a lot of symbolic representations.

Wednesday October 27

Today started off as a usual day in Mr.H's 3rd period class. Mr.H opened up the previous night's blog written by neil and examined what he had wrote about. This post included and overview of how a few problems from packet pages were done and other things of that sort.
Next Mr. H gave us a few tips on how to study for the test the following day.

The 3 sources Mr.H Advised us to take a gander at were

• The Moodle Practice Quiz
• Delicous Pages
• Look back in the packets
• Look at the blog(what your doing now WOAH!!!!)
• Look into the book

After explaining our test prep, Mr. H assigned us a new problem that would be due on friday. This problem was appropriately named "Crash Of Avagadro Flight 1023." In this problem you are a forensic scientist trying to find out who murdered the unlucky suspect before the plane crashed. You are given tests of various peoples clothes and other belongings that tell you the percent composition of the substances found.

Your job was to identify the substances and to find the murderer. This problem consisted of converting a percent composition into an empirical formula to find suspects and then linking that data to a single murderer.

For the last 15 minutes of class Mr. H let us loose to start the problems in our lab groups.

Tuesday, October 26th

Today, Chemistry class started off just like any other day by reviewing the blog that was written the night before. Shidan had written about finding the empirical formula when giving the molar mass of a compound and percents of specific elements in a compound. Mr. H reminded us of what homework was due upcoming. That included a Webassign that was due on Thursday and the fact that we had a upcoming test on Thursday.

We began the day with work in our packet with problem 3 on page 13. This problem was a two part problem asking to name two different compounds. One compound was an oxide with 50.0% Sulfur and the other was another oxide with 40.0% Sulfur. The percents were by mass. First, we began with the compound that contained 50.0% Sulfur. To begin the problem Mr. H told us that we could assume that there were 100g of the compound. So with that information were able to conclude that there were 50g of of Sulfur in the substance. Next, we had to find the number of moles in Sulfur and to do that the number of grams of Sulfur in the substance was divided by the molar mass of Sulfur. This equaled 1.559 mols. Then, we had to find the number of moles of oxygen in 50g of Oxygen. It was 50g because there was 100g of the substance and 50g of sulfur, so this was the left over amount. The total amount of grams of Oxygen in the substance was then divided by the molar mass of Oxygen which was 16.00 rounded. This equation equaled 3.125 mols. The two equations for calculation mols are below on the blog and in the picture.

Mols of Sulfur: 50g x (1 mol/32.07g)=1.559 mols.
Mols of Oxygen: 50g x (1 mol/16.00g)=3.125 mols.

The next step was finding the ratio of oxygen atoms to sulfur atoms which was found by the equation y/x. Y being oxygen and X being sulfur. The ratio in this compound approximately when rounded 2:1. For every two oxygen atoms there were one sulfur atom. The empirical formula was SO2. The name of the compound was sulfur dioxide, which was a topic that we covered in Unit 2.

After completing the first part of the problem, Mr. H told us to the second part on our own. Following the same steps as above it was assumed that there were 100g of the substance, and because 40% was Sulfur it there were 40g of Sulfur and 60g of Oxygen. Next the number of mols was calculated just like above by the following equations.

Mols of Sulfur: 40.0g x (1 mol/32.07g)=1.247 mols.
Mols of Oxygen: 60.0g x (1 mol/16.00g)=3.75 mols.

Next, the same formula for finding the ratio was used as previously to conclude that the ratio of Oxygen atoms to Sulfur atoms was approximately 3.00 when rounded. We were able to conclude that the empirical formula was SO3. Again, we had to name the molecular compund and it was Sulfur Trioxide.

Picture of the problem that we did in class on packet page 13.
After the problem, we switched to a second lab that was an extension of the lab that we had done the previous day. It was focused around making specific calculations with the information that we are given. Since this lab was very dangerous, Mr. H did it himself as the class watched. Mr. H performed a reaction where before the reaction there were 91.46g of Sucrose with the beaker and after there were 67.28g of of Carbon with the beaker. The third piece of data that we had was the mass of the beaker which was 50.66g. The three calculations that we had to make where the mass of Sucrose, Carbon and H20. The mass of Sucrose was found by taking the subtracting the mass of the sucrose with the beaker and subtracting the mass of the beaker. There were 40.80 g. The mass of carbon was the mass of carbon after the reaction which was 67.28g was subtracted by the mass of the beaker which meant that there were 16.62g of Carbon in Sucrose. The mass of H20 was the mass of sucrose subtracted by the mass of carbon. The mass of H20 was 24.18g. Then, the percents of Carbon and H20 in sucrose was found. The equations follows.

%C: 16.62g/40.80 x 100=40.7%
%H20: 100%-40.7%=59.3%

This extension lab that we completed perfectly complimented the lab that we had worked on the previous day which was Lab MR3. With the help of learning how to do the new calculations we were able to successfully complete our individual labs. The demonstration for the lab follows and the password to gain access to the video is gbs.
http://www.dropshots.com/chemistryclassroom#date/2010-10-25/20:33:04

Working on the labs in our groups brought us to the end of class. Before class ended, Mr. H repeated what the homework was for the night.

Monday, October 25th

In chemistry today, we started out by receiving our grades. Mr Henderson also reminded us of our Test on Thursday along with our delicious bookmark which is due at the end of the unit. Then we moved on to our lesson of the day which was mass composition and empirical and molecular formulas. Our lesson for today was on the packet page 13. We started out by finding the molecular or empirical formula’s of certain compounds with a given molar mass. As an example in the compound Octane, the molar mass was 114.2 g/mol, and the molecular formula was given to be C8H18. Mr. Henderson then explained that the empirical formula was C4H9 because it was the simplest ratio of the molecular formula.

In a second example, we were given the compound Benzene and the molar mass was 78.1 g/mol. The empirical formula CH was given and there are many possibilities for a molecular compound from this formula, so the Mr Henderson explained how you can find the molecular formula through the molar mass. For this problem we found that the mass of Benzene was six times that of the empirical formula, so therefor the molecular formula would be C6H6.

We then did a word problem together where we had to determine the empirical and molecular formula of an unknown carbohydrate when given the percent ratios of the elements and the molar mass. We solved this by assuming that that there was 100.00g of this substance, then we multiplied each of the percentages by their molar masses and from this we got the empirical formula which we compared with the molar mass to get the molecular formula.

Finally we finished the class with the Formula of a Hydrate Lab. In this lab we had to determine the chemical formula of the hydrate of copper sulfate by weighing the copper sulfate before and after we burned all the moisture out of it.

Friday, October 15 - Unit 3

Friday was test day. We took the Unit 2 test with 33 multiple choice questions and one page of naming and formula writing with a short calculation. There were 50 questions worth 2 points each. Up-to-date grade printouts will be available on Monday.  This day marks the official end of Unit 2. 

Unit 3 will continue on Monday. (We've already had a day and a half of this unit, in which we learned how to use conversion factors and the meaning of the atomic mass unit and relative atomic masses.) As we continue through Unit 3 we will learn about the mathematical relationships associated with the chemical formulas. We will learn that a chemical formula reveals quantitative information about the gram-to-gram and atom-to-atom relationships for the elements within a chemical compound. This unit will be the first of several math intensive units within the course.

Friday October 22nd

Today’s class began with a celebration of mole day! We then looked through last night’s blog post. After, we worked on pages 11 and 12 of our unit packet, which is about molar mass and percent composition. These are the steps to find figure that out,

1) Write out the formula for the ionic compound
2) Figure out how many atoms there are for each of the elements
3) Multiply the number of atoms by the mass number for each of the elements
4) Add that all together to find the total molar mass (g/mol)
5) To find the percent composition, divide the molar mass for each atom by the total molar mass 6) Once the answer is found, add 100, so the number is a percent
7) Do the same for each of the atoms (the percents should be equal to 100)

For example, iron (III) carbonate has a formular of Fe2(CO3)3. This contains 2 atoms of Fe, 3 atoms of C, and 9 atoms of O. The mass number of iron is 55.857, which is multiplied by 2 because there's 2 atoms of it. Then, add 3x12.011 (Carbon) and 9x15.99 (Oxygen). This number is 291.72 g/mol, which is the molar mass. To find the percent composition, 55.847x2 divided by 291.78 and add 100, which is 38.3 percent. The percentages for Carbon and Oxygen are 12.4% and 49.3%. Mr H also taught us a shortcut to find the 3 percent: add the 2 previous percentages and subtract that from 100.

For extra help on percent compositions, http://www.ausetute.com.au/percentc.html gives a thorough and detailed explanation and provides examples.

The answers for page 12, the answers should look like this:

After doing pages 11 and 12, we went over yesterday’s lab and turned in our lab notebooks to be graded. Our lab notebooks included lab MR1 (the H20 Challenge Lab) and MR2 (Chew on This! Lab). To finish class, we took a short quiz over 3.1 and 3.2, which included many conversions.

Thursday, October 21

For some unknown reason, the period began with the majority of the class talking about poetry. After sharing one of his own Mole poems, Mr. H announced that Mole day would be celebrated tomorrow. Students were encouraged to contribute to the food pantry, though the sign had spelled the word as "panty" and we all had a laugh. Then, we went over yesterday's blog post by Kyle and Mr. H explained today's subjects. First we would go over packet page 10, then learn "something important."

Mr. H went over the relationship between particles, moles, and mass, and made a rather inappropriate pun involving molasses. Then, we solved problems 4 and 7 viewable below.

The rest of the period was spent on the Chew on This Lab and packet page 11. For the lab, we were going to determine the percent composition of sugar in gum. We measured the mass of the un-chewed gum with the wrapper and the wrapper by itself. While we chewed the gum to extract the sugar, we learned how to calculate percent composition. To do this, one had to find the molar mass of each element in a compound, divide that by the molar mass of the entire compound, and multiply the quantity by 100. After going through an example, iron (III) carbonate, Mr. H told us that page 11 would be a homework assignment due sometime next week.

At that moment, we had chewed our gum long enough to extract the majority of the sugar. We went to the scales in the back of the room to take the mass of the sugarless gum with the wrapper. Subtracting the wrapper's mass, we found the mass of the gum with sugar (un-chewed) and the mass of the gum without sugar (chewed). Subtracting the mass of the sugarless gum from the mass of the gum with sugar revealed the mass of the sugar in that one piece of gum. We followed the procedure for calculating percent composition and each of us got a unique answer. According to the manufacturer, this percent is approximately 80%, though this value can vary quite a bit. Mr. H made one last joke by instructing us on how to "properly" dispose of our gum: by sticking the piece under our individual desks.

Our homework is to do a WebAssign and finish our Unit 3 Delicious assignments. Our lab notebooks are also due at the end of class tomorrow, so don't forget!

Wednesday, October 20

Mr. H started off the class by telling us why not to tell mole jokes because they are molelitically incorrect. He then began to tell some mole jokes about Avogadro and his number, 6.022*10^23. After cracking some mole jokes, Mr. H told us to take out our packet and turn to pages 6 and 7.

We began to review the molar mass of compounds and the mole and atomic mass. The first problem we started on page 7 was 7 and our task was to find the formula for the compound and then determine the molar mass of the compound. In order to solve this problem, you must first figure out the formula for the compound barium nitrate. Barium has a plus 2 charge and nitrate has a minus one charge, and you have to switch these numbers due to the principal of electrical neutrality. The formula would be Ba(NO3)2. Then you must find the atomic mass of barium which is 137.33, nitrogen which is 14.01 * 2=28.02, and oxygen is 16.00 * 6=96. Now you add all of them together and you get 361.35g/mol.

After we finished this, Mr. H taught us how to do mole conversions on page 9. The most important part to remember is the relationships between Particles(atoms, molecules) <==> Moles, use Avogadro's number, Moles <==> Mass, use molar mass.
The answers to the three problems are:
1. 12.16mol

2. a. 1.48 * 10624

b. 98g/mol

3. 2.59 * 10^22 molecules

Then we went to the science computer lab to work on our webassigns for the rest of the period.
HW: 3.2 Molecules<==> Moles<==>Mass Part 1 due Friday, Part 2 due Monday and Unit 3 Delicious Bookmark due Tuesday.

Tuesday, October 19

Converting to Atoms, Moles, and other measurements
After going over last nights blog and talking to us about national mole week, Mr. Henderson began to focus in on the big idea for the day. Just as we have been doing for the past week or so, we started off by converting one unit to another. However, today we started with slightly more difficult conversion problems. Of course, I'm talking about converting moles to atoms, atoms to moles, atoms to grams, grams to moles and so on. Before I begin to go over pages 6 and 7 (the pages we worked on today), it is important to have a basic understand for some of the quantities we will be addressing.

First off, the one you will be hearing most about in this blog is the mole. 1 mole is 6.022x10^23 of something. This number was created to help us convert one atom to a useful unit, like the gram. This leads into my next point, the mass of atoms. On our periodic table, the mass of an element is known as XX amu's. This number can also be used to obtain the elements grams per mole. How you do this is actually very very very very simple. Take the atomic mass of the element and drop it into the g/mol unit! So, for example, oxygen's atomic mass is about 16 amu's. Therefore, oxygen is also 16g/mol. This is used so that we can speak of the units of each element in more relative terms, such as grams or grams per mole.

Now lets begin going over the packet pages starting with pg.6. The top of page 6 asks how many donuts or in 2 dozen donuts. This question is there to help us understand that a mole is nothing more than a way to help us speak more easily about atoms, like a baker uses the dozen to talk about the number of donuts he is baking. The next question asks how many atoms are in 2 moles of water. Since we know that 1 mole of atoms is 6.022x10^23, we automatically know that 2 moles of water would be 12.044^23 atoms, or 2 x 1 mole of atoms. Questions 4-6 are very similar and are used to help us understand just how large a mole is. The first question asks how much mass would 1 mole of .62kg basketballs have? So, as we would start of all conversions, we begin with the unit we are given which is 1 mole of basketballs, in this case. Now, our next step would be to put 6.022x10^23 basketballs / 1 mole of basketballs. Our final calculation would be to multiply the mass of a basketball / 1 basketball. We are now left with (6.022x10^23)x.62 kg. After doing these calculations, we get the answer......... 3.7kg x 10^23! If you still don't understand just how massive this is, the mass of the of the moon is also given. It is only 7.4x10^22. 1 mole of basketballs is 5 times as massive as the very moon that orbits our Earth!

(Yup, that moon)

Next, on Questions 7-9, we began to use the mole for what it is truly meant for; Converting atoms to more useful units of measurement. Our first question is How many atoms of lead(Pb) are in 5.0x10^-4 grams of lead? Now lets begin our conversion with 5.0x10^-4 g of Pb. Because we are looking to obtain a number of atoms as our answer, we will start with the next corresponding conversion factor, the mole. 1mole/207.2 g of Pb should be your next step because this is the number of grams that would result from 1 mole of lead atoms. Also, as we discussed earlier, it is the same amount as the atomic mass of lead on the periodic table. Finally, we will multiply 6.022x10^23 atoms/ 1 mole to cancel out our moles and get an answer. Although 0.0005 grams of lead may seem like a small amount relative to our everyday lives, It is still 1.45 x 10^18 atoms of lead! A massive number of atoms for a minuscule amount of grams.


The answer for pages 6 are as follows:

#1)24 donuts
#2)12.044x10^23 molecules
#3)10 (every power added to 10 multiplies the given amount by 10, in this case, moles)
#4)3.7 x 10^23kg
#5)3.8 x 10^ 14 years
#6)3.6 x 10^26 cubic centimeters
#7)1,45 x 10^18 atoms
#8)9.0 x 10^18 atoms
#9) 2.1 x 10^-22 grams (that's 0.000000000000000000000021 grams!)

As for pg 7, we just began to discuss the molar mass of compounds and the way to do this is probably the way you would have guessed. Just add together the mass of each elements in the compound. To obtain the molar mass of Barium Chloride (BaCl2), add the mass of 1 mole of barium atoms(137.33 g/mol) to the mass of 2 moles of chloride atoms (2 x 35.34 g/mol). Your answer should add up to 208.23 g/mol. We will continue on to finish this sheet tomorrow but all the answers we have gotten in class so far are as follows.

#1) 32 g/mol
#2) 58.45 g/mol
#2.5) H20= 18 g/mol (IMPORTANT FOR LAB MR1.)
#4) 208.23 g/mol

With the final 10 minutes of class, Mr. Henderson let us get back to our lab groups and finish up the lab with the knowledge that we had gained from question #2.5 on pg.7. Now we know that water is about 18 g/mol. Next, each group would have to find the amount of moles that was assigned to your group. This could be done by dividing the amount of molecules assigned to each group and dividing it by 6.022x 10^23 Luckily, all our group were assigned a number of molecules that could easily be divided by a mole. Finally, all that had to be done to solve this seemingly impossible conversion was to multiply the number of moles your group had by the grams per mole (g/mol) of water, which we know is 18 g/mol. Now you would be left with xx grams of water, and since we know water's density is 1 gram per milliliter, the last step was to change grams into mL and present your findings to Mr.Henderson.

I hope this blog helped clear up any confusion about molar mass and atomic conversions. Today was definitely a jam packed day. Good Luck!

Monday, October 18, 2010

Who is Amadeo Avogadro? Why, only the most famous scientist ever! Why is he so famous? He thought of the mole, that's why. The mole is a scientific unit. It is used in measurement, mostly in chemistry. The mole is abbreviated as "mol". But why is this significant? Today, we started Unit 3. Unit 3 focuses on stoichiometry, or the science that deals with the quantitative relationships that exist between products and reactants. (conversion factors) The number mole, is mathematically written as 6.022 x 10 to the 23rd

To begin our class today, Mr. Henderson passed back our grade reports, with the Unit 2 Test inscribed upon its face. Mr. Henderson also told us about the National Mole Week recently declared by President Obama. With that, we began class.

We took some notes and filled out a leaf of paper in our Unit 3 Packet. It focused on finding the number of moles of a certain atom in some situations and and finding the number of atoms in others. These are two very different ideas. Using conversion factors we learned earlier, we were able to make short work of these four problems we were given. Mr. Henderson also showed us how to find the number of atoms in a certain mass of an element. For example, let's take 12.01 grams of carbon. The number of atoms for this amount of carbon would be 6.022e23. (1 mole) How did we get that? The average atomic mass of carbon is 12.01. If you have an atom, with its average atomic mass in grams, just put down one mole as your answer. However, if the mass in grams is slightly smaller or larger than your given atom's AAM, you take the 6.022 from the mole and divide or multiply accordingly. For example, let's say you had 20 grams of calcium. The AAM for calcium is about 40. Because this is half, you would take 6.022 and divide by two. Your answer shall be 3.011 x 10 to the 23rd. (you keep the last part of the number)

To end the class, we started our MR1 lab. (after getting new lab groups and moving to new seats) This is the H2O challenge lab. We have to count how many molecules there are in a sample of water. Since we cannot see molecules, we must count them in a different way. By using the mol, of course. We add the AAM of two hydrogen atoms to the AAM of one oxygen atom. However, not everyone finished this lab in class today and Mr. Henderson will let us finish it tomorrow. For anything else check his website.

Friday, October 15

Friday was test day. We took the Unit 2 test with 33 multiple choice questions and one page of naming and formula writing with a short calculation. There were 50 questions worth 2 points each. Up-to-date grade printouts will be available on Monday.  This day marks the official end of Unit 2. 

Unit 3 will continue on Monday. (We've already had a day and a half of this unit, in which we learned how to use conversion factors and the meaning of the atomic mass unit and relative atomic masses.) As we continue through Unit 3 we will learn about the mathematical relationships associated with the chemical formulas. We will learn that a chemical formula reveals quantitative information about the gram-to-gram and atom-to-atom relationships for the elements within a chemical compound. This unit will be the first of several math intensive units within the course.

Thursday October 14, 2010

Today, Mr H began today's lesson by going over Matt's blog and pointing out some of the specifics that he had included such as how to do conversions and how to find the average atomic mass from multiple isotopes.

Mr. H then went over what was included in tomorrow's 90 point test. The test includes:

1) 33 multiple choice questions
2) a writing section
         a. writing formulas and names of ionic/molecular compounds
         b. a math problem like #3 on the bottom of page 14

After explaining the contents of the test, Mr. H told the class 6 different ways to study for this test. These included:

1) Looking at students' blogs from unit 2
         a. this is a good place to look, because many students have included specific formulas as well as methods on how to name ionic and molecular compounds

2) Looking at Delicious bookmarks
         a. this is also another great place to look, because not only can you study from your bookmark, but if you need help in other things from unit 2, you can study from the bookmarks done by other students

3) Looking over web assigns from unit 2
         a. This is one of the best places to look because not only can you study the answers that you got correct, but you can also study the problems that you got wrong.
                         I. in order to see the answers to the ones that you got wrong, click on the 'view key' box that is located at the top of every web assign. This box is there now, because once the due date passes for every assignment, that box pops up so students can see the answers to the questions they got wrong.

4) Looking over the unit 2 packet
          a. this is a great place to look if you are lost on certain things or if you want more practice because there are many pages filled with practice problems as well as explanations on everything in unit 2.

5) Doing the practice test that can be found on moodle. Here are the steps:
                a. Go to moodle and sign in
                b. click on Honors chem meta course
                c. under the "worksheets" tab, click on unit 2
                d. now click on the document that contains that specific thing that you want help on or want to study more. Here is the link if you are having difficulty finding it: http://gbs-moodle.glenbrook225.org/moodle/mod/resource/view.php?id=1045

6) Rereading the sections from unit 2
               a. this can be very helpful, but if you don't want to reread these sections, then i would recommend doing #s1-5

^^^^^^^ this is what the meta course page looks like after you've done all the steps ^^^^^^^^^^^


After explaining to us all the multiple ways to study, Mr. H had the class open their unit 3 packets to page 1. Mr. H went talked about all the wild conversions that we did (i.e. converting stinkups to dollars). Mr. H went on to explain that its important to be able to convert numbers no matter how wild the units are.

Mr. H then worked with the entire class to solve #4 on page 2. He explained to us that when you cancel out units, you need to make sure that you cancel the same units that are in the numerator and denominator of the problem. After canceling these units, you would multiply all the numerators together and then divide by each denominator. Here is what it would look like:

6 dopes= 11.8 napos  x 2.9 bicnics  x 17.8 blurches  = 25.4 blurches 

3 dopes      4 napos              12 bicnics

After doing this, we turned to page 4 of our unit 3 packets, and Mr. H explained to the class how atomic mass and atoms are related. For instance, if you had 24.02 amu of carbon, you would have 2 atoms of carbon. this is because 1 atom of carbon is 12.01amu. If you were to double 12.01, you would get 24.02. This is how you would solve for the number of atoms in an amu of a certain element.

For most of the day, Mr. H had gone over what the test was going to look like; that way we would be prepared for the test. Be sure to STUDY!!!!

Wednesday, October 13, 2010

To begin class we opened up our unit 2 packets to page 14. Here Mr. Henderson reviewed how a mass spectrometer is a device that measures the average atomic mass of different isotopes of an element. We then reviewed how to do problems one and two which were problems finding the average atomic mass of elements.

We then pretended that number three of page 14 was a test question. After we finished this Mr. Henderson started to talk about the test. To begin he put a slight twist the problem number three. Instead of having both percentages of abundance and atomic mass units for both isotopes, you might only have one percentage of abundance and atomic mass units, but you will also have a periodic table.

For example, if number three of page 14 said, "Determine the atomic mass and abundance of isotope 65 copper if isotope 63 copper occurs naturally as 69.09%."

To find the abundance: 100% (in nature)-69.09% (isotope 63)

This would equal to 30.91% (isotope 65).

To find the atomic mass unit: first find copper's atomic mass on the periodic table (63.55 amu)

Now you can set up an equation relating these terms

63.55 (average atomic mass unit)=.6909(abundance-isotope 63) x 62.93(relative mass) + .3091(abundance-isotope 65)X(relative mass)

Simplify: 63.55 = 43.48 + .3091X

20.07 = .3091X

64.93 = X

Isotope 65 Copper has a relative atomic mass unit of 64.93.

If you need help with this concept please visit: http://www.algebralab.com/practice/practice.aspx?file=Algebra_AverageAtomicMass.xml

Also on the test, there will be 35 multiple choice questions. We will have to know the history of atoms and what scientists contributed, isotope notation, the periodic table (periods, groups, and families), cations and anions, and naming of compounds. Furthermore, there will be one page (write and show work section) that you will need to know how to convert formulas into names and names into formulas. In this section there will be a problem similar to the example I described above.

We continued class by going over yesterday's blog and started unit 3. We immediately started conversion-factor problems on page one. Mr. Henderson taught us how to convert decades into seconds or even puggets into illies. You can do this by using easy information that you already know either common knowledge or the knowledge they give you in the problem.

For example, if I wanted to find out how many seconds are in a day, I would use this conversion-factor method. I know that there are 24 hours in 2 days. I also know that there are 60 minutes in 1 hour and 60 seconds in 1 minute. So, I would set up my expression like this:

2 days* 24 hrs 60 minutes 60 seconds

1 day * 1 hour *1 minute

I then would cancel out the same units because I know that units that are "upstairs" cancel out with the same units "downstairs."

So, my new equation would be:

2 *24*60*60 seconds

1

So, there are 172,800 seconds in 2 days.

After working busily on page one, the bell rang and class was over. We accomplished a lot on a day when we had shortened classes.

October 12, 2010

Tues, 10-12-10

We began our class today by admiring yesterday's blog, and then we were given the answers to pages 21 and 22.

1. c

2. a

3a. Na(+1) 3b. Al(+3) 3c. N(-3)

3d. F(-1) 3e. Ba(+2) 3f. Se(-2)

4. c

5. -1

6. -2

7. a

8a. BaCl2 8b. Al2O3

8c. NH4Cl 8d. Na3SO4

9. b

10. c

11. a

12. d, a, b

13. b

14. c

15. c, b, a

16. a

Atomic Mass:

Then we got back our quiz, and proceeded to talk about atomic mass. We learned that the atomic mass listed on the periodic table is the average of the most common atomic masses of an element. In order to find the atomic mass you do not weigh the atom, but instead you compare 1 atoms mass to another. In order to find this difference, you must shoot the atoms through a magnetic field, and compare how much 1 atom bends (upward or downward) to how much another atom bends. The more an atom bends, the greater the atomic mass. (Pg. 14 for help).This diagram shows the atoms in the magnetic field.

We then learned how to find the average atomic mass of an element. You take the isotopes provided (ex Boron-10= boron with atom mass 10) and take the abundance in the earth, and multiply to find the average mass of boron or any element. Take number 1 on pg. 14 for example and do the following: (multiplication sign is *)

#1 Pg. 14:

.198*10.1+.802*11= 10.8 amu

- .198 and .802 represent the abundance on earth of that isotope, while 10.1 and 11 represent the masses.

-when doing this you label the atomic mass as amu

If you are given: Find which isotope of element y is more present in the environment using the periodic table. Then you find which atomic mass the element is closest to, and that is the most common in nature.

ex: Boron's atomic is 10.81 because 10.81 rounds to 11, you know boron-11 is more

common in nature

Math:

Today, we also briefly talked about how to do unit conversions. You use the Factor Label Method.

This rule is based off the idea that if a=b, then a/b=1.

ex: find the number of centimeters in 1 mile

Steps:

1. you begin by putting 1mile over 1

2. you cancel out miles by putting 5280ft over 1miles

3. you cancel out feet by putting 12in over 1ft

4. you cancel out inches by putting 2.58cm over 1in

A= 160934 cm/miles (centimeters per mile)

For help on factor label method go to: http://library.thinkquest.org/2923/basic.html ,

or http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson24.htm

HW:

-webassign

Monday, October 11, 2010

We walked into class today and were automatically instructed to pick up our graded composition lab notebooks already waiting on the back lab benches. After the class returned to their desks, Mr. Henderson put up the seat chart and asked for volunteers to contribute to our blog. Following the blogging business, Mr. H quickly reminded us of the "pop" quiz we had today and told us to take out our unit 2 packets and turn to page 10.

Once on page 10, Mr. H proceeded to remind us about the difference between ionic and molecular (covalent) bonds (compounds).

• ionic (eye-ohn-ik): compounds between cations (metals) and anions (non-metals)
• molecular (muhl-ehk-yoo-lur): compounds between only anions

We then started to complete page 10. Part one was identified as ionic compounds and we therefore knew we were dealing with metals. The answers are as followed:

a) Magnessium iodide

b) Sodium sulfide

c) Calcium bromide

d) (Typo possibly?)

Next, we identified part two as ionic compounds with multi-valent cations (transitional metals). The answers are as followed:

a) Copper(II) chloride

b) Cobalt(II) sulfide

c) Manganese(III) chloride

d) Copper(I) sulfide

For polyatomic ions (part 3), we only went over b. The answer is Ammonium sulfide.

For part 4, the reverse was to be done. The answer to e was (NH4)2S and to f was (NH4)3PO4.

Mr. H then reminded us the "training wheels" when formulating compounds. He told us to first identify the charges of the ions and the properties of balancing charges and then begin to put together the formula.

Subsequently, we were re-taught how to put together the formulas of molecular compounds. Greek prefixes must be used to indicate the number of atoms of each element in the compound. The only exception to this rule is cases in which there is only one atom of the first element. Further practice can be found on page 11 in the packet.

Our review ended with a quick lesson on putting together the formulas of acids. They generally have the chemical formula HX where X is the nonmetal. Their names take the form of hydro(anion root)ic acid.

( i.e. hydrochloric acid - HCl)

The general formula of an acid and how to create it can be found in Daria's blog before me although remember:

-ate --> -ic

-ite --> -ous

Before passing out our quizzes, Mr. H showed us a brief video on experimenting with the reactions between water and alkali metals. The video can be accessed here:

http://www.youtube.com/watch?v=eCk0lYB_8c0

After this, Mr. H handed out Periodic tables and our pop quizzes and....

THE END!

Y

Friday October 8th, 2010

Today we started out class normally as we always do by checking the previous nights blog and doing attendance.

After that we opened up page 11 and we finished it. Mr. Henderson told us not to forget the Greek prefixes, and that two was di not bi as normally used. Also, 8-octa, 9-

nona, and 10-deca. He also recommended we use the PT to help us finish the page. A oddball thing I noticed was that

when doing 4 atoms of oxygen instead of doing tetraoxide as most people would think, its actually teroxide.

After page 11 we started on page 12, which we didn't finish but we got a good start on. on this

page we were figuring out if the compounds were molecular or ionic. Ionic compounds are formed by nonmetals and metals forming and they also DO NOT use Greek prefixes. Molecular compounds are made by 2 nonmetals and there can only be 2 elements. Don't forget to put

the roman numerals if transition metals are used!

After page 12 Mr. Henderson introduced how to write names for acids and gave us some notes which are pictured on the left. We then started doing page 13. Mr. Henderson told us that almost all the acids we were going to talk about were going to have a formula that started with H. if u need extra help on naming acids all the rules are on page 43 in our chemistry books.

After learning about acids, Mr.Henderson told us to turn in our lab notebooks and we headed off to the computer lab to work on anything we had in mind. Then Mr.Henderson reminded us to work on our webassigns and that there is going to be a popquiz on monday!

Thursday October7, 2010

Mr. Henderson began class by jumping right into page 9 in our packet.
We had already started page 9 yesterday. Page 9 is on names and
formulas of ionic compounds. For example we would be given a formula
such as BaSO4 and we would separate it into cation (Ba2+) and anion
(SO2/4-) as well as writing its name (barium sulfate). When you come
across a formula like SO you can look at the back of your periodic
table given out in class. There you can find what name corresponds
with the symbol and how the mass number and atomic number correspond.
Mr H. reminded us multiple times during our work on page 9 that roman
numerals are only used for transition metals as well as tin and lead.
Next we turned to page 11 in our packets. Page 11 is on names and
formulas of molecular compounds. The class found this page far easier.
The first part focused on greek prefixes. For example we would be
given a formula like CF4 and we would find the name(carbon
tetrafluoride) of the compound. Tetra is used as the prefix because
the number 4 was after the symbol F. The second part of page 11 we
were given a name and had to write the formula. For example we were
given the name phosphorus pentafluoride and had to find the
formula(PF5).
The second half of class was spent in the math computer lab working on
other work such as our notebooks which are due tomorrow(Friday). Class
ended with Mr. H handing back graded work and a current grade report.

Wednesday, October6

Today was a normal day in Mr.H’s third period class. We started by going over Tim’s blog post. He then recapped the future assignments such as the oleic acid lab in the first five minutes of class. Mr.H then sent us into our packets to page 9 where we began with the first three problems as a somewhat recap of what we did on Tuesday. Then we went into the “newer” material for the day.

This consisted of the new kind of ion that we would be learning about named the polyatomic atom. Polyatomic ions are special ions that end in suffixes such as –ite or-ate. These special ions were coincidentally placed on the reverse of the “PT” that Mr. H gave us a few days before.

After this short discussion we were sent off into the computer lab to work on future web assigns and other homework.

Heres a link to a wikipedia of polyatomic ions

http://en.wikipedia.org/wiki/Polyatomic_ion

And a table of Polyatomic Ions

http://www.texaseducator.com/family/jbouyer/lessons/Science/askew/mycourses/polyion.gif

Tuesday, October 5

Like always, class started with a quick recap of last night's blog and yesterday's lesson. Mr. Henderson gave us a heads up on coming up assignments and a little of whats going to happen this week. He reminded us that we have several webassign assignments and labs that were due.

After that, Mr. Henderson told us to open up to page seven, where we would learn how to name ionic compounds. We were given a set of chemical formulas and names of ionic compounds. We were told to find patterns in them. In the chemical formula, we found that the subscripts on the formula give info about the charges on the ions. He said that they followed the principle of electrical neutrality, which means that the sum of all positively charged ions always equal the sum of all the negatively charged ions. In the names of the ionic compound we found that they were made up of two words. The first part was metal, which was then followed by a non-metal. The first word was always the actual name of th

e metal, while the second word ended with -ide. Also, we found that in ionic compounds di- and tri- were not used. Then, we were given problems five and six to solve. On problem five we were given four chemical formulas, which we were suppose to name. The answers to problem five were:

NaBr-Sodium Bromide BaO- Barium Oxide CaF2-Calcium Fluoride Al₂S3-Aluminum Sulfide

On problem six we were give names of four ionic compound, which we were suppose to write the chemical formula. The answers to problem six were:

potassium chloride- KCl sodium sulfide-Na₂S

calcium bromide- CaBr₂ aluminum fluoride- AlF₃

After we were done with page seven, we moved to page eight. On this page, we had to name ionic compounds, but they were different than the ones on page seven. They had roman numerals next to their names. The roman numerals represented the charge of the metals. Also, all the metals were transition metals and Pb+Sn. All these metals could posses different types of charges. For example, iron could have 2, 3, or 5 charges and rarely 4 or 6 charges. Afterwards, we were given problems six and seven to complete. Problem six was similar to problem five on page seven and problem seven was similar to problem six on page seven. The answers to problem six were:

FeBr₃- iron (III) bromide

NiS- nickel (II) sulfide

CoCl₂- cobolt (II) chloride

FeBr₂- iron (II) bromide

AuCl₃- gold (III) chloride

SnF₂- tin (II) fluoride

The answers to problem seven were:

copper (I) chloride- CuCl iron (III)oxide- Fe₂O₃

tin (IV) fluoride- SnF₄ iron (II)sulfide- FeS

After answering the problems on page eight, class ended. For homework, we were given a choice to do some of the work at home or to work on it at the computer lab tomorrow. If you require a more detailed explanation on how to name ionic compounds, I recommend you check out this website.

http://chemistry.about.com/od/nomenclature/a/nomenclature-ionic-compounds.htm

Friday, October 1

Today we started out our day as we always do, we went over the previous nights’ blog and recapped all the important ideas we learned yesterday. We also got a quick preview of the sodium experiment we were going to do during today’s class period.


After we finished going over the blog Mr. Henderson told us to open up our packets to page five. This page was going to help us learn about ions. Ions are negatively or positively charged particles. In other words anything with a charge is considered an ion. There are two types of ions: Cantions, which are positive and have more protons then elections, and Anions, which are negative and have more elections then protons. Mr. Henderson gave us a great way of remembering which one is which, for Anion he told us, A N Ions, which stands for A= a, N=negative, Ions=ion, so a negative ion! Also, all metals tend to form positive ions and all non-metals tend to form negative ions.

In the worksheet there was some hard questions with multiple answers that seemed right but really weren’t. For example, in numbers 3 and 4 we are given 6 answers to choose from, but Mr. Henderson made it easy. He gave us an easy way to make some answers obviously wrong. He said that, splitting nucleuses causes atomic bombs so obviously that’s not what an ion is. But, splitting elections is. So in numbers 3 and 4, four of the answers are wrong at first sight since they say losing a proton, gaining a proton etc. So were left with two answers for each question which makes it twice as easy to pick the right one.

For number five Mr. Henderson told us that “Atoms of most elements want to be like HeNeArKrXeRn.” Therefore when looking for the charges of atoms, all you have to do is either subtract the atomic number to make one of the atoms in group 18 or add to the atomic number to make one. This makes making ions so much easier.

For today we skipped number six. But we did half of number seven and left the last two for Monday. Number seven is an easy practice question which we have done on page two and gotten a lot of practice on it. But this time there’s a twist, you add ions. When writing an ion you write the charge (+,-) then the number, for example the first element we do is magnesium-24 ion. The isotopic symbol is ₁₂²⁴Mg^+2.

^{After doing page 5 Mr. Henderson showed us by far one of the coolest demos we have ever done. It was dropping sodium in water, and it made for a great show. The sodium, which is highly reactive in water since it is in group one, started fizzing and going in a circle. It was really cool.}

Mr. Henderson showed us what sodium looks like when it comes out of the container. It was a little rusty looking and defiantly not shiny.

Mr. Henderson demonstrates how sodium “cuts like butter”.

After cutting the sodium, it is REALLY shiny and nice looking.

Here is a link to the video so you can see exactly what happened, remember the password to sign in is gbs. http://www.dropshots.com/chemistryclassroom#date/2010-09-30/21:41:02

After these fun activities we finished the class with a couple videos and Mr. Henderson giving us a preview of the homework and of what we’re going to do on Monday.

The first video we showed was http://www.youtube.com/watch?v=GDMUb5mQsjo. That video showed a not so exciting Caesium in water video from the funny haired guy. Since the reaction was not so exciting the whole class decided to watch a better reaction, which was http://www.youtube.com/user/periodicvideos#p/search/6/5aD6HwUE2c0. That gave off a VERY big reaction and was sufficient for our curiosity.

After the videos Mr. Henderson told us we are officially done with section four and sections 5 and 6 are going to take a week or a little more after that. During next week, on Tuesday and Wednesday we are going to be in the computer lab. We are going to be working on lab 4, which Mr. Henderson is going to explain, and on web assigns that we have not completed yet.

 In lab number four we have a lot of data to get; since we are done in the back of the room with this lab Mr. Henderson was nice enough to record the rest of the data on the homepage of his chemistry honors website. It is located under the title “Help is Hear!” That recording will help you with the rest of the lab, but we will be doing that on Tuesday and Wednesday.

 Finally Mr. Henderson finished the exciting day in the chemistry room. The homework for next time was a web assign due Monday on chapter 2.4, and an ongoing assignment to complete your lab notebook, which is due Friday.

 If you need any help on ions I recommend these two websites. In the first site they help with naming the ions, which you will learn in chapters 2.5 and 2.6 but if you would like to get a head start this site is a good preview. In the second website there is a magnificent review of how to figure out the charges of ions and how to make compounds neutral. I definitely recommend the second website for a review for the test.

http://www.mpcfaculty.net/mark_bishop/ionic_nomenclature_help.htm

http://www.wisc-online.com/objects/ViewObject.aspx?ID=gch2104

 

 

 

. 

 

Monday, October 4

Monday, October 4

Today we began Mr. Henderson's class by looking at Friday's blog post. Then talking briefly about the web-assign that was due Monday. Then we reviewed how to determine the number of protons, number of neutrons, and the element name based off the following: (To the left)

Then we proceeded by doing lab #AM15. We conducted a series of experiments that we used to determine if a an unknown substance was a metal, nonmetal, or metalloid. We organized our data into a chart and determined the physical and chemical properties of substances A, B, C, D, E, F, G, and H. However when doing the assignment we didn't find the chemical reaction of CuCl2 (Copper Chloride), but instead repla

ced it with HCl2 (Hydrochloric Acid).

After filling out the data section, we proceeded to take a 20 minute quiz on the material which we covered last week.

For Help Visit:

http://periodic.lanl.gov/use.html (Periodic Table Help)

http://www.mikeblaber.org/oldwine/chm1045/notes/Periodic/Metals/Period06.htm (Metals vs Nonmetals vs Metalloids)

http://www.wisc-online.com/Objects/ViewObject.aspx?ID=gch3604 (Ions)

http://www.colorado.edu/physics/2000/isotopes/index.html (Isotopes)

Friday, October 1, 2010

Friday October 1, 2010

Today we started out our day as we always do, we went over the previous nights’ blog and recapped all the important ideas we learned yesterday. We also got a quick preview of the sodium experiment we were going to do during today’s class period.

After we finished going over the blog Mr. Henderson told us to open up our packets to page five. This page was going to help us learn about ions. Ions are negatively or positively charged particles. In other words anything with a charge is considered an ion. There are two types of ions: Cantions, which are positive and have more protons then elections, and Anions, which are negative and have more elections then protons. Mr. Henderson gave us a great way of remembering which one is which, for Anion he told us, A N Ions, which stands for A= a, N=negative, Ions=ion, so a negative ion! Also, all metals tend to form positive ions and all non-metals tend to form negative ions.

In the worksheet there was some hard questions with multiple answers that seemed right but really weren’t. For example, in numbers 3 and 4 we are given 6 answers to choose from, but Mr. Henderson made it easy. He gave us an easy way to make some answers obviously wrong. He said that, splitting nucleuses causes atomic bombs so obviously that’s not what an ion is. But, splitting elections is. So in numbers 3 and 4, four of the answers are wrong at first sight since they say losing a proton, gaining a proton etc. So were left with two answers for each question which makes it twice as easy to pick the right one.

For number five Mr. Henderson told us that “Atoms of most elements want to be like HeNeArKrXeRn.” Therefore when looking for the charges of atoms, all you have to do is either subtract the atomic number to make one of the atoms in group 18 or add to the atomic number to make one. This makes making ions so much easier.

For today we skipped number six. But we did half of number seven and left the last two for Monday. Number seven is an easy practice question which we have done on page two and gotten a lot of practice on it. But this time there’s a twist, you add ions. When writing an ion you write the charge (+,-) then the number, for example the first element we do is magnesium-24 ion. The isotopic symbol is ₁₂²⁴Mg⁺².

After doing page 5 Mr. Henderson showed us by far one of the coolest demos we have ever done. It was dropping sodium in water, and it made for a great show. The sodium, which is highly reactive in water since it is in group one, started fizzing and going in a circle. It was really cool.

In the first picture Mr. Henderson showed us what sodium looks like when it comes out of the container. It was a little rusty looking and defiantly not shiny.

In the second picture Mr. Henderson demonstrates how sodium “cuts like butter”.

In the third picture after cutting the sodium, it is REALLY shiny and nice looking.

Here is a link to the video so you can see exactly what happened, remember the password to sign in is gbs. http://www.dropshots.com/chemistryclassroom#date/2010-09-30/21:41:02

After these fun activities we finished the class with a couple videos and Mr. Henderson giving us a preview of the homework and of what we’re going to do on Monday.

The first video we showed was http://www.youtube.com/watch?v=GDMUb5mQsjo. That video showed a not so exciting Caesium in water video from the funny haired guy. Since the reaction was not so exciting the whole class decided to watch a better reaction, which was http://www.youtube.com/user/periodicvideos#p/search/6/5aD6HwUE2c0. That gave off a VERY big reaction and was sufficient for our curiosity.

After the videos Mr. Henderson told us we are officially done with section four and sections 5 and 6 are going to take a week or a little more after that. During next week, on Tuesday and Wednesday we are going to be in the computer lab. We are going to be working on lab 4, which Mr. Henderson is going to explain, and on web assigns that we have not completed yet.

In lab number four we have a lot of data to get; since we are done in the back of the room with this lab Mr. Henderson was nice enough to record the rest of the data on t

he homepage of his chemistry honors website. It is located under the title “Help is Hear!” That recording will help you with the rest of the lab, but we will be doing that on Wednesday and Thursday.

Finally Mr. Henderson finished the exciting day in the chemistry room. The homework for next time was a web assign due Monday on chapter 2.4, and an ongoing assignment to complete your lab notebook, which is due Friday.

If you need any help on ions I recommend these two websites. In the first site they help with naming the ions, which you will learn in chapters 2.

5 and 2.6 but if you would like to get a head start this site is a good preview. In the second website there is a magnificent review of how to figure out the charges of ions and how to make compounds neutral. I defiantly recommend the second website for a review for the test.

http://www.mpcfaculty.net/mark_bishop/ionic_nomenclature_help.htm

http://www.wisc-online.com/objects/ViewObject.aspx?ID=gch2104