Answer to Question #182352 in General Chemistry for Daniela(me)

Question

7. A 50.0 mL sample of gas is cooled from 119 °C to 80.0 °C. If the pressure remains constant, what is the final volume of the gas? (45.0 mL)

Answer 1

V₁ = 50.0 mL

T₁ = 119°C + 273 = 392 K

P₁ = P₂ = const

V₂ = unknown

T₂ = 80.0°C + 273 = 353 K

Solution:

Since the pressure doesn't change, Charles' Law can be used.

Charles' Law can be expressed as: V₁ / T₁ = V₂ / T₂

V₁T₂ = V₂T₁

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

V₂ = V₁T₂ / T₁

V₂ = (50.0 mL × 353 K) / (392 K) = 45.0255 mL = 45.0 mL

V₂ = 45.0 mL