Notes for Thursday, Jan. 14, 2010

Well, I don't know about you, but I could use some more blog credits so here are my notes for the day. They're pretty sparse because I take short notes when I'm not blogging, but it's better than nothing.

• Composition stoichiometry deals with the mass relationships of elements in compounds.
• Reaction stoichiometry involves the mass relationships between reactants and products in a chemical reaction.

There are four types of problems that were discussed in detail.

1. Amount of given substance (mol) --> amount of unknown substance (mol)
2. Amount of given substance (mol) --> amount of unknown substance (mol) --> amount of unknown substance (g)
3. Amount of given substance (g) --> amount of given substance (mol) --> amount of unknown substance (mol)
4. Amount of given substance (g) --> amount of given substance (mol) --> amount of unknown substance (mol) --> amount of unknown substance (g)

There could also be problems involving volume or formula units, but we didn't list those in the big four. There was a chart that's in the book, but I don't want to reproduce it. It could make a nice comment, though. Hint hint wink wink.

• A mole ratio relates the amount of moles of any substance involved in a chemical reaction.

Answers to Problems 5 and 6 on page 320

5. a. 5.0 mol H2

b. 2.5 mol O2

6. a. 15.8 mols O2

b. 9.0 mols CO2, and 13.5 mols H2O

Homework

HW 4: complete activity 3-11 from class.
HW5: complete problems 7-10 on page 320.

As always with a Jim Alrutz blog post, tomorrow's poster will be chosen with the power of random.org. Unless somebody wants to volunteer, with it being a three day weekend and all. By my watch it's past the standard blog post deadline, so I'm posting this. Good night, and have a pleasant tomorrow.