Untitled Lesson

Unit 7 Review
Gas Laws

1 mol of gas = 22.4 L at STP

​Volume of ideal gases

1 atm = 101 kPa = 760 mmHg
0 ^oC = 273 K

​STP

Gases at STP

Multiple Choice

What volume will 4.3 mol of H₂ gas occupy at STP?

• 12 L

• 57 L

• 96 L

• 23 L

Multiple Choice

How many moles of oxygen gas occupy 3.8L at STP?

• 0.24 moles

• 0.13 moles

• 0.17 moles

• 0.30 moles

Math Response

How many GRAMS of oxygen gas occupy 45L at STP?

Type answer here

Correct Answer: 64

Deg^°

Rad

Since the same number of L is occupied by 1 mol of every ideal gas, we can use the liters in place of moles.

​mol ≈ L

In a chemical equation

Example

2H₂ + O₂ --> 2H₂O

How many liters of hydrogen gas would be needed to react with 17L of oxygen gas to produce water?

Example -- solution

Use ratios with the coefficients

Use this when there is a change in status of the gas.
If a quantity is not addressed or is held constant, simply set it equal to 1.

Use this when there is no change in the status of a gas.
R is the universal gas constant.
It will be given
T MUST BE IN KELVIN

​PV = nRT

Gas Laws

Dalton's Law

​pressures add

The partial pressure for each gas will add to the total pressure.

Percentages will add to 100.

IMFs

​IMFs relate to boiling points

Substances with higher IMFs have higher boiling points.

Substances with lower IMFs have lower boiling points.