1. Moles and Gas Volume (3.4)
Avogadro’s Hypothesis: equal volumes of different gases at the same temperature and pressure contain the same number of particles.
Molar Volume of a Gas (at STP):
22.4 L = 1 mol
STP: Standard Temperature and Pressure
Temperature = 0oC (or 273 K)
Pressure = 1 atm (or kPa)
this relationship can be used for unit conversions between “moles” and “L” for any gas

2. What is the volume (in L) occupied by 0.350 mol of SO2 (g) at STP?
How many moles are in 3.74 L of H2 (g) at STP?
What is the mass of 3.45 L of O2 (g) at STP?
How many atoms of oxygen are in 2.50 L of CO2 (g) at STP?