Using the combined gas law, calculate the the volume, in mL, at STP of a gas that has a volume of 150.0 mL at 1.20 atm and 293 K.?

Initial : P₁ = 1.20 atm, V₁ = 150.0 mL, T₁ = 293 K
At STP : P₂ = 1.00 atm, V₂ = ? mL, T₂ = 273 K

Combined gas law : P₁V₁/T₁ = P₂V₂/T₂
Then, V₂ = V₁ × (P₁/P₂) × (T₂/T₁)

Volume at STP, V₂ = 150.0 × (1.20/1.00) × (273/293) mL = 167.7 mL