% Composition and Empirical Formulas

We calculated % composition for known compounds and then used % composition of unknown compounds to calculate their formula.


Homework:

1. Watch: Limiting Reactants
2. Do: WSQ - Limiting Reactants

Magnesium oxide lab

Well, not everything went quite as planned in the lab.  Some reactions didn't happen all the way.  Some crucibles got too hot, but it's okay.

Science is messy.

Please find someone with good lab data and borrow that to complete the lab.  Don't forget to cite your source and explain what happened to your experiment in your error analysis.


Homework:

1. Finish lab report.
2. Watch: % Composition & Empirical Formula
3. Do: WSQ - Empirical Formula

Mass - Mass conversions

Today we converted mass of reactants into mass of products.  Great job!

Next time, we will do a lab.

Homework:

1. Read: Magnesium oxide lab (this is based from a lab done at Christian Brothers HS in Memphis).
2. Do: WSQ - Magnesium oxide lab
3. Write (optional): Start writing your lab report.  You do not need to do the prelab questions yet.

Mass Problems

Today:

1. Moles --> Mass
2. Mass --> Moles
3. Atoms --> Mass
4. Mass --> Atoms
5. Formula Mass

If you're not getting this stuff, please come see me.  Everything is going to build upon the early stuff so save trouble by getting it now.

Homework:

  No new video, but try these problems to make sure that you understand.

Moles

Welcome back!

Here's what we learned today:

1. A mole is a really big number: 6.02x10^23 things.
2. Moles are only really useful for counting very small things.
3. The atomic mass tells you the mass per mole of that atom.

Homework:

1. Do: read the chapter.
2. Watch: Mass
3. Do: WSQ-Mass