Chemistry finding equilibrium concentration

Question

A mixture of 3.51 mol N2 and 35.21 g NO is heated in a closed vessel to 2000C. After heating, the total pressure of the mixture at equilibrium is 3.14 atm. Calculate the equilibrium partial pressures of N2, O2 and NO at 2000C.

Answer 1

A mixture of 3.51 mol N₂ and 35.21 g NO is heated in a closed vessel to 2000C⁰. After heating, the total pressure of the mixture at equilibrium is 3.14 atm. Calculate the equilibrium partial pressures of N₂, O₂and NO at 2000 C⁰ ?

SOLUTION

GIVEN DATA

Reaction: N_2(g) + O_2(g) → 2 NO_(g)

Mol N_2(g) = 3.51 mol

Mol O_2(g) = 1.00 mol

Mol NO_(g) = 35.21 g / 30.0061 g/mol = 1.17 mol and 2 NO = 2 (1.17) = 2.35 mol

Total pressure = 3.14 atm

Mol fraction of N_2(g) = 3.51 / 3.51 + 1.00 + 2.35 = 0.51

Mol fraction of O_2(g) = 1.00 / 3.51 + 1.00 + 2.35 = 0.15

Mol fraction of NO_(g) = 2.35 / 3.51 + 1.00 + 2.35 = 0.34

Partial pressure = Total pressure x mole fraction

Partial pressure of N_2(g) = 3.14 atm x 0.51 = 1.60 atm

Partial pressure of O_2(g) = 3.14 atm x 0.15 = 0.49 atm

Partial pressure of NO_(g) = 3.14 atm x 0.34 = 1.07 atm