Gas Laws Practice Test

A steel container holds 56 liters of a gas at 1.4 atm pressure.  What volume would the gas occupy at 1.5 atm?

• 52 L

• 0.04 L

• 60 L

• 118 L

Answer explanation

You are given volume (liters) and pressure (atm). This means you use Boyle's Law.

P₁V₁ = P₂V₂

P₁ : 1.4 atm

V₁ : 56 L

P₂ : 1.5 atm
V₂ : x

A sample of helium has a pressure of 202.6 kPa in a 150 mL container.  If the container is compressed to 50 mL, what is the new pressure?   Assume temperature is constant.

• 37.0 kPa

• 20260 kPa

• 67.5 kPa

• 607.8 kPa

Answer explanation

You are given volume (mL) and pressure (kPa). This means you use Boyle's Law.

P₁V₁ = P₂V₂

P₁ : 202.6 kPa

V₁ : 150 mL

P₂ : x
V₂ : 50 mL

A 7.0 liter balloon at room temperature (22^oC) contains hydrogen gas.  If the balloon is carried outside to where the temperature is –3.0^oC, what volume will the balloon occupy?

• 0.95 L

• 6.41 L

• 7.65 L

• 273 L

A small sample of helium gas occupies 6 mL at a temperature of 250 K.  At what temperature does the volume expand to 9 mL? 

• 125 K

• 375 K

• 500 K

• 2250 K

If the pressure in a steel gas cylinder containing oxygen were 37.5 atm at 22^oC, what would the pressure be at a temperature of 300^o C?

• 777 atm

• 511 atm

• 72.8 atm

• 2.75 atm

Tags

NGSS.HS-PS3-2

A gas has a pressure of 3.5 atm at 40.0˚C.  What is the temperature at standard pressure?

• 3.05 K

• 11.4 K

• 89.4 K

• 273 K

What volume does 0.056 moles of hydrogen gas occupy at 25 ^oC and 1.11 atm pressure?
R = 0.0821 L·atm/mol·K

• 1.23 L

• 0.103 L

• 100 L

• 12.3 L

Answer explanation

You are given moles, temperature and pressure. You will be using Ideal Gas Laws.

PV = nRT

P: 1.11 atm

V: x

n: 0.056 moles

R: 0.0821

T: 25°C + 273 = 298K

Calculate the number of moles of gas contained in a 3.0 L vessel at 300 K with a pressure of 1.5 atm.  R = 0.0821 L·atm/mol·K

• 0.10 moles

• 0.015 moles

• 0.36 moles

• 0.18 moles

Answer explanation

You are given volume (L), temperature (K), and pressure (atm). This will use Ideal Gas Law.

PV=nRT

P: 1.5 atm

V: 3.0 L

n: x

R: 0.0821

T: 300K

When a sample of a gas is kept at a constant temperature and the volume is increased, the pressure will .

• increase

• decrease

• remain constant

• vary

Answer explanation

When a question says "constant", that variable can be disregarded. For instance, this problem says "constant temperature", that means the temperature will not have any impact on the situation.

Boyle's Law states that volume and pressure have an indirect relationship (as one goes up, the other goes down and vice versa).

A child has a balloon in his house in the air conditioning.  He goes outside with the balloon on a hot day.  What happens to the temperature of the gas and volume of the balloon?

• temperature increases, volume increases

• temperature increases, volume decreases

• temperature decreases, volume increases

• temperature decreases, volume decreases

Answer explanation

Charles' Law states that volume and temperature have a direct relationship. If one increases, the other increases. If one decreases, the other also decreases.

Tags

NGSS.HS-PS3-2