Answer to Question #222201 in Chemistry for caleb villarreal

Question

If I have 21 liters of gas held at a pressure of 78 atm and a temperature of 900. K, what will be the volume of the gas if I decrease the pressure to 52 atm and decrease the temperature to 750 K? (round to sig figs)

Answer 1

P₁ = 78 atm

V₁ = 21 L

T₁ = 900 K

P₂ = 52 atm

V₂ = unknown

T₂ = 750 K

Solution:

Combined Gas Law can be used:

P₁V₁/T₁ = P₂V₂/T₂

Cross-multiply to clear the fractions:

P₁V₁T₂ = P₂V₂T₁

Divide to isolate V₂:

V₂ = (P₁V₁T₂) / (P₂T₁)

Plug in the numbers and solve for V₂:

V₂ = (78 atm × 21 L × 750 K) / (52 atm × 900 K) = 26.25 L = 26 L

V₂ = 26 L

Answer: 26 L