Question

Question 5.15 Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm^3 at 27°C. R = 0.083 bar dm3 K–1 mol–1.

Class XI States of Matter Page 153

Answer 1

given, mass of O2 = 8g
molar mass of O2 = 32
mole of O2 = given weight/molar mass of O2
= 8/32 = 0.25 mol

Given weight of H2 = 4g
molar mass of H2 = 2g
mole of H2 = given weight of H2/molar mass of H2 = 4/2 = 2 mol

total number of mole = 0.25 + 2 = 2.25 mol
now, use formula,
PV = nRT
here V = 1 dm³ , T = 300K , R = 0.083 bar dm³/K/mol, P = ?
P = nRT/V
= 2.25 × 0.083 × 300/1
= 56.025 bar

hence, P = 56.025 bar