Question

If the temperature of a 1.75 liter sample of gas is changed from 30.0°c to 20.0°c at constant pressure, what will be the new volume? question 3 options:

Answer 1

According to Charles' law, "at constant pressure the volume of a gas is directly proportional to absolute temperature".

So, for a gas, initial and final states are given as,

V₁ / T₁ = V₂ / T₂

Data Given:
V₁ = 1.75 L

T₁ = 30 °C + 273 = 303 K

V₂ = ?

T₂ = 20 °C + 273 = 293 K

Solving Eq. 1 for V₂,

V₂ = V₁ T₂ / T₁

Putting Values,

V₂ = (1.75 L × 293 K) ÷ 303 K

V₂ = 1.69 L
Result:
As temperature is decreased so volume has also decreased to 1.69 L.