Goes with powerpoint for chapter 10 notes

1. Chapter 10 Notes—ALL ABOUT THE MOLE!
How do I calculate molar mass?
STEP 1:
STEP 2:
STEP 3:
STEP 4:
What is a mole?
TRY IT OUT!
Find the molar masses of:
NaCl H2
O
SO3
PCl3
MOLAR MASS!

2. EVERYTHING GOES THROUGH THE MOLE!
WHAT IS A TWO-STEP CONVERSION PROBLEM?
Calculate the number of molecules in 60.0 g NO2.
1st
Conversion:
2nd
Conversion:
So here’s an example!
Here’s the equation:

3. How many moles is 2.80 X 1024
atoms of silicon?
How many moles is 2.17 X 1023
particles of bromine?
How many moles are in 20 grams of NaCl?
Determine the volume in liters of 5 moles of hydrogen gas.
Another example:
Calculate the volume, in liters, of 3.24 x 1022 molecules of Cl2 (STP).
LET’S PRACTICE!

4. Calculating Percent Composition
Step 1:
Step 2:
Step 3:
Step 4:
Let’s Practice:
What is the percent composition of PbCO 4 ?
• When no formula is given, take the numbers that are given and add them together
to get a total.
• Divide each number by the total and multiply by 100 to get the percent.
EMPIRICAL FORMULA
• What is an empirical formula?

5. • This is a formula that gives the lowest whole number ratio of atoms in a
compound.
• It’s similar to reducing fractions.
Calculating Empirical Formula
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:

6. Let’s Practice:
A compound is analyzed and found to contain 13.5 g Ca, 10.8 g O and .675 g H. What is
the empirical formula of the compound?
Molecular Formula
• Molecular formula is similar to empirical formula.
• It is a multiple of the empirical formula and reflects the actual chemical formula.
Step 1:
Step 2:
Step 3:
Step 4:

7. Let’s Practice!
A compound with the empirical formula of C2OH4 has a molar mass of 88 grams per
mole. What is its molecular formula? Hint: the empirical formula has already been
calculated for you.
Topics on the test:
*Calculate molar mass
*Convert Moles, liters, grams and molecules/atoms using mole road.
*Calculate percent composition
*Calculate empirical formula
*Calculate molecular formula