Unit 10, Day 2

Class began by Mr. H briefly explaining the demo we were supposed to do today. He explained that there was a solution in the buret of sodium acetate that was slowly dripping out to form the "stalagmite" looking white substance underneath. However, the solution was not quite hot enough and hadn't reached its full solubilty (50 g of solid in 5 mL of water) so we had to wait. Next we moved on to page 21 (a reading assignment from Monday). Mr H. also noted that in his demo from yesterday he had tricked us because there was a nonpolar substance in the beaker before the water was added so what was really burning was that unknown substance floating on top. The answers are as follows:
1- a
2- c
3- d
4- c
5- a
6- b
7- a
8- Polar solvents dissolve polar (and ionic) solutes. Nonpolar solvents dissolve nonpolar solutes. <- main idea from yesterday 9- d 10- b 11- c 12- a 13- a 14- a Note on side column: Water-soluble vitamins: B's and C

• excreted daily (if not used)
• contain O-H bonds
• must be consumed daily

Fat-soluble vitamins: D A K E

• stored in body tissue
  
• not excreted via urine
• can be toxic

Next we moved on to page 11. First we did number 13 and learned the reason oil and water don't mix is because oil in nonpolar and water is polar so the attraction is not there. Then we moved back up to number 10 and explained after looking back at number 8, that CS2 or CCl4 would be the best options to dissolve the paint because they are both nonpolar like the oil paint and therefore would be able to clean it off. This is why soap is better at getting dirt out then water which is similar to number 14 which again shows that water is polar and oils and dirts are nonpolar so there is no attraction. Before moving on to new material we went over number 15 on the next page. Because the SO4 bond is polar due to the electronegativity the water molecules would be towards the right end. Oppositely the C-H bonds are nonpolar because the electronegativity is right at .4 so the oil molecules would be attracted to the left side. Finally we moved on to the new material on page 15 which was similar to the webassign due Wednesday. We knew that number 1 was no because of how different all the lines were on the graph. For number 2 the answer was that as a gases' temperature went up the gas solubility went down (which was the opposite for solids). After Neil broke the stalagmite class was over and everyone was pissed at Neil. The end.