Monday, September 20

Today Mr. Henderson started the day out by signing up the remainder of people for blog days if they have not already done the blogging. He then goes on to tell our class that today we will be doing a lab test. The lab test will be done throughout today and tomorrow.

Homework: Labs #5, 6, and 7 are due Tuesday (tomorrow)

webassign is due Wednesday

TEST THURSDAY

FOR THE TEST, STUDY FROM THE BLOG, TEXTBOOK, AND OBJECTIVE SHEET FOUND IN THE UNIT PACKET.

A sheet was then handed out explaining what should be included in the labs which will be turned in tomorrow.

Mr. Henderson then began to explain what our class is going to be doing for the rest of the week. Tomorrow we will continue working on the sugar lab and then have a lab test. Then we will review for the test Thursday. Wednesday we will be starting to learn about the next unit. Thursday is the test and on Friday first someone from the TLC will be coming to talk to our class and then we will be going to the computer lab.

Next Mr. Henderson told our class to take out our Chemistry Basics packet while he opened Anthony's blog from the previous day (Friday). After looking at the blog we turned to page 13 in our packets and worked on problem #5, which said if a piece of aluminum has a mass of 14.0 g, what volume does it occupy?(the density of aluminum=2.70 g/cm cubed). To find the answer, Mr. Henderson set up the equation volume=mass/density=14.0g/2.70g per cm cubed. The answer when put into the calculator came out to be 5.185185185185. Using the significant digits rule the answer is 5.19 cm cubed. We also learned the answer could be 5.19 mL because cm cubed equals mL.

The next problem we did was #11 on page #14. The question was several beads of an unknown metal are placed into a partially-filled graduated cylinder. The water level in the graduated rises from 24.58 mL to 49.12 mL. The mass of the beads was determined to be 127.88 g. Determine the density of the metal. To solve the problem Mr. Henderson set up the equation density=mass/volume=127.88g/24.54mL. The volume was found by subtracting 49.12-24.58=24.54 mL. 127.88g/24.54mL=5.21108. Using the significant figures rule the answer is 5.211g per mL.

Once we finished the 2 problems Mr. Henderson went on to tell us that for our test on Thursday that we will have to know how to do the percent difference(difference between the 2 measures/average of the 2 measure x 100) and find the density of a substance(density=mass/volume).

Then it was time to start the lab for the day. Mr.Henderson explained that the purpose of the lab is to determine the percent sugar in each of the beverages. What percent of the beverage is sugar? The reason why we would want to know this is because sugar contributes to the mass. The beverages used are made mostly of water and sugar but also flavorings and dies.

Today we did the first part of the lab which was finding the mass and volume of water that had either 0%, 5%, 10%, 15% or 20% of sugar in it. These measurements would be used to determine the amount of sugar in the beverages which would be tested tomorrow. Mr. Henderson then reminded our class to wear our safety goggles and to dispose of the sugar water in the sink. Also he then explained how to use the pipets by turning the wheel.

In the lab, as expected, it was found that the more sugar the water contained, the higher its mass. The mass of the 0% sugar water was 4.97g, 5% was 5.03g, 10% was 5.07g, 15% was 5.16g, and the 20% was 5.25g. The volume of the 5 substances was a constant 5.00 mL.

This is a picture of my lab group’s data table from lab #8

This is a picture of the rubric which will used to grade the labs.