Question

[28] a gas occupies 560 cm^3 at STP. Find it's volume when.
[a] pressure is 700mm of mercury and temperature is 27°C
[b] pressure is 800mm of mercury and temperature is -173°C​

Answer 1

a)  0.668 L ≅ 668 cm³

b)  0.195 L ≅ 195 cm³

Explanation:    

Given: P₂ = 700 mmHg = 700/760 = 0.92 atm, T₂ = 27 + 273 = 300 K,

            V₂ = ?, V₁ = 560 cm³ = 0.56 L, T₁ = 273 K, P₁ = 1 atm

we know that,

a) P₁V₁/T₁ = P₂V₂/T₂

           V₂ = P₁V₁T₂ /P₂T₁

                = 1 × 0.56 × 300/0.92 × 273

                = 0.668 L ≅ 668 cm³

b) V₂ = P₁V₁T₂ /P₂T₁

         = 1 × 0.56 × 100.15/ 1.05 × 273

         = 0.195 L ≅ 195 cm³