Unit 8 Gases IHS Henry

Boyle’s Law

• P₁V₁ = P₂V₂

• Indirect relationship

Charles’ Law

• V₁/T₁ = V₂/T₂

• Direct relationship

Gay-Lussac’s Law

• P₁/T₁ = P₂/T₂

• Direct relationship

Combined Gas Law

• P₁V₁/T₁ = P₂V₂/T₂

Ideal Gas Law

• PV=nRT

• When at STP:

  • atm = 1.00

  • mol = 1.00

  • temp = 273 K

  • vol = 22.4 L

Given that gas = constant pressure

What happens to volume when temperature is doubled?

Volume is doubled

• V₁/T₁ = V₂/T₂

  • 1/1 = V₂/2

    • V₂ = 2

Given that gas = constant volume

What happens to temperature when pressure is halved?

Temperature is halved

• P₁/T₁ = P₂/T₂

  • 2/1 = 1/T₂

    • T₂ = 1

Given that gas = constant temperature

What happens to pressure when volume is doubled?

Pressure is halved

• P₁V₁ = P₂V₂

  • (1)(1) = (P₂)(2)

    • P₂ = ½

Given that pressure is doubled and volume is halved

What happens to the temperature?

Temperature will stay the same

• P₁V₁/T₁ = P₂V₂/T₂

  • (1)(2)/(1) = (2)(1)/(T₂)

    • T₂ = 1

Given that both temperature and volume are doubled

What happens to the pressure?

Pressure will stay the same

• P₁V₁/T₁ = P₂V₂/T₂

  • (1)(1)/(1) = (P₂)(2)/(2)

    • P₂ = 1

Motion of gases (KMT)

Gases are in constant random motion

Collisions of gas particles (KMT)

Gas particle collisions are elastic, meaning energy is conserved

How does gas fill containers/spaces (KMT)

Gases spread out to fill containers/spaces

How much space does gas particles take up in a space (KMT)

Gas particles take up an insignificant amount of space in a sample

Density of gases (KMT)

Gases have relatively low density (g/L) compared to solids and liquids

Pressure of gases (KMT)

Gas pressure wants to be equal and flows from high to low

IMFs in gases (KMT)

~ about no IMFs

Absolute Zero (0 Kelvin)

When particles have no kinetic energy, and stops moving (in theory; humans have never been able to achieve absolute zero)