Chapter 6: Unit 8. STP

STP

Avogadro’s law allows us to compare the amount of any two gases by comparing their volumes. Often amounts of gas are compared at a set of standard conditins of temperature and pressure called STP.

STP conditions are: 1 atm ( 760 mm of Pr) and 273 K ( (0⁰C)

At STP, one mole of any gas has the same volume 22.4 L called the standard molar volume.

Example:

1mol= 22.4 L

Q: How many mols are present Moles of 5.00 L of O₂ at STP?

1mol                  = x mol

22.4 L                   5.00L        x= 0.223 mols

At STP all different gases occupy same volume.

Questions:

1. Burning 1mol of propane in a gas grill occupies 150. grams of CO₂. What volume of CO2 does it occupy at STP?

Ans: 76.3L