Question

Density of mixture is 1.84g/l at temp 380 k and pressure 1 atm. Find kp for reaction

Answer 1

Given,

Density of mixture, d = 1.84 g L⁻¹

Temperature of the mixture, T = 380 K

Pressure of the mixture, P = 1 atm

From ideal gas law,

Density, d = $\frac{P × M}{R × T}$ ;

where R is universal gas constant, R = 0.082 L atm mol⁻¹ K⁻¹ and M is the molar mass of the mixture.

⇒ M = $\frac{d × R × T}{P}$

       = $\frac{d × R × T}{P}$

       = $\frac{(1.84 g L⁻¹) × (0.082 L atm mol⁻¹ K⁻¹) × (380 K)}{1 atm}$

       =  57.33 g mol⁻¹

For a equilibrium mixture, Kp can be calulated by the multiplication of mole fraction and pressure of the mixture, P.