Into to stoich.

Today, pages 3,4,5 and 6 were stamped. We went over the answers, and they should be posted on moodle.
We were supposed to take the first stoich quiz today, but it has been moved to Monday.

We worked on pg 9, 10, 11, and 12 which were intros to stoich. Most of the pages were review from the particulate nature unit. We reviewed how to balance equations.

Remember- the same amount of each atoms had to be on both sides of the equation.

We also learned how to figure out how much of each atom you need to balance an equation.


Example: 4Fe + 3O2 -> 2Fe2O3

How many molecules of oxygen would you need to react with 380 atoms of iron?

To figure out the answer to this question, you start with what you know. You know you have 380 atoms of iron. According to the equation above, you know that for ever 3 molecules of O2 you have, their are 4Fe atoms. Therefore the equation should be like this:

380Fe x 3 molecules of O2 = 285 molecules of O2
4 molecules of Fe

This is simple stoichiometry. To use stoich, you much always start with a balanced chemical equation.

We also filled out pg 14, which is more of this simple stoich.

Pages 15 and 16 are for homework. They will be stamped on Monday.
Remember the quiz had been moved to Monday!

-Rima S.