Answer to Question #178917 in Chemistry for Nghi

Question

. At a pressure of 1.5 atm and 42.2 °C, a certain gas has a volume of 340.0 mL. What will be the volume of this gas under STP.

 

Answer 1

Solution:

STP conditions (a temperature of 273.15 K and a pressure of 1 atm).

Hence,

P₁ = 1.5 atm

V₁ = 340.0 mL

T₁ = 42.2°C + 273.15 = 315.35 K

P₂ = 1.0 atm

V₂ = unknown

T₂ = 273.15 K

The 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 = (1.5 atm × 340.0 mL × 273.15 K) / (1.0 atm × 315.35 K) = 441.75 mL = 441.8 mL

V₂ = 441.8 mL

Answer: The volume of this gas will be 441.8 mL.