Unit 10 Gases and Gas Law

Which of the following is NOT an assumption of the Kinetic Molecular Theory?

• Gas particles are in constant, random motion.
• Gas particles attract and repel each other.
• The volume of gas particles is negligible.
• Collisions between particles are elastic.
• Temperature reflects average kinetic energy.

Answer explanation

KMT assumes no intermolecular forces (no attraction/repulsion).

Which unit of pressure is equivalent to 1 atm?

• 101.3 kPa
• 500 mmHg
• 14.7 Pa
• 760 psi
• 273 K

Answer explanation

1 atm = 760 mmHg = 101.3 kPa

What is standard temperature in Kelvin?

Answer explanation

Standard temperature is 273 K (0°C).

Gas particles have which of the following properties?

• No fixed shape
• Compressible
• Expand to fill container
• Strong intermolecular forces
• Move randomly

Answer explanation

Gas particles are compressible, mobile, and fill containers.

Convert 0°C to Kelvin.

Answer explanation

K = °C + 273 → 0 + 273 = 273 K

Which of the following describes the motion of ideal gas particles?

• Vibrate in place
• Move randomly with elastic collisions
• Stay stationary
• Follow predictable curves
• Repel each other

Answer explanation

Ideal gases move randomly and collide elastically.

What is the pressure in atm of 405 mmHg?

Answer explanation

405 mmHg ÷ 760 = 0.533 atm

Which of these conditions will cause a gas to deviate from ideal behavior?

• High temperature, low pressure
• Low temperature, high pressure
• STP conditions
• Dry gas only
• Graham’s conditions

Answer explanation

Real gases deviate under low temp/high pressure.

According to Boyle’s Law, what happens to pressure if volume decreases?

• Pressure increases
• Pressure decreases
• Temperature increases
• Volume increases
• Moles double

Answer explanation

Boyle’s Law: pressure and volume are inversely related.

Boyle’s Law formula is:

• P₁V₁ = P₂V₂
• V₁/T₁ = V₂/T₂
• P/T = constant
• PV = nRT
• P₁/T₁ = P₂/T₂

Answer explanation

Boyle’s Law: P₁V₁ = P₂V₂