Chemistry Test Gas Laws 2

Question 1

A gas occupies 4.0 L at 2.0 atm. What volume does it occupy at 0.5 atm (constant temperature)?

Accepted Answer

16.0 L

Answer

By Boyle's Law, P1V1 = P2V2: (2.0)(4.0) = (0.5)(V2), so V2 = 16.0 L.

Question 2

A gas at 300 K occupies 6.0 L. At what temperature will it occupy 9.0 L at constant pressure?

Accepted Answer

450 K

Answer

By Charles's Law, V1/T1 = V2/T2: 6.0/300 = 9.0/T2, giving T2 = 450 K.

Question 3

What does the van der Waals equation correct for compared to the ideal gas law?

Accepted Answer

Both molecular volume and intermolecular attractions

Answer

The van der Waals equation adds correction terms for finite molecular volume (b) and intermolecular attractions (a).

Question 4

Which gas law is applied when a sealed rigid container is heated, causing pressure to increase?

Accepted Answer

Gay-Lussac's Law

Answer

Gay-Lussac's Law states that at constant volume, pressure is directly proportional to temperature.

Question 5

Using the ideal gas law, how many moles of gas are in a 22.4 L container at STP?

Accepted Answer

1.0 mol

Answer

At STP (273.15 K, 1 atm), one mole of ideal gas occupies exactly 22.4 L by definition.

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