1. Drill – 3/24/11
How much does a mole of boron weigh?
How many atoms of boron are in a mole?

2. Molar Volume

3. Equal volumes of gases at the same temperature and pressure contain equal number of particles.
No matter what the size of the gas particle, large empty space exists between individual particles of gas.

4. Because temperature and pressure affect the volume of a gas (↑T = ↑ V ↑P =↓V) we use a standard temperature and pressure (STP) to measure volume.
STP
T is 0ºC or 273K
P is 101.3kPa or 1 atm

5. At STP, 1 mol or 6.022x1023 particles of any gas will occupy a volume of 22.4L.
22.4L = Molar Volume
Know this number!!

6. Molar Volume is used in conversions and stoichiometry.
Volume of gas = moles of gas X
1 mole

7. 0.375 mole of O2 will have what volume at STP?
Example:
0.375 mole of O2 will have what volume at STP?
22.4 L O2
0.375 mol O2 X
= 8.40 L of O2
1 mol O2

8. 30 mL of hydrogen are produced from the decomposition of water
30 mL of hydrogen are produced from the decomposition of water. What volume of oxygen is formed?