Answer to Question #119759 in Chemistry for aljoc

Question

A 2.75 L sample of helium gas at 99.0 kPa was heated from 21.0°C to 71.0°C and the pressure changed to 100.0 kPa. Calculate the final volume.

Answer 1

P₁ = 99.0 kPa

V₁ = 2.75 L

T₁ = 21.0°C = 294 K

P₂ = 100.0 kPa

V₂ = unknown

T₂ = 71.0°C = 344 K

Solution:

The Combined Gas Law can be used.

The Combined Gas Law can be expressed as:

P₁V₁/T₁ = P₂V₂/T₂

Cross-multiply to clear the fractions:

P₁V₁T₂ = P₂V₂T₁

Divide to isolate V₂:

V₂ = (P₁V₁T₂) / (P₂T₁)

To find the final volume, solve the equation for V₂:

V₂ = (99.0 kPa × 2.75 L × 344 K) / (100.0 kPa × 294 K) = 3.1855 L = 3.19 L

V₂ = 3.19 L

 

Answer: 3.19 L is the final volume.