For $2 SO X_{2} (g) + O X_{2} (g) 2 SO X_{3} (g)$ , $K_{p} = 0.40 at m^{- 1}$ at 800 K. Use $R = 0.0821 L atm mo l^{- 1} K^{- 1}$ and calculate $K_{c}$ (in $L mo l^{- 1}$ ) to the nearest integer.

Numerical answer type, answer in L/mol, tolerance 0.5.

Answer: 26 L/mol

Δ n_{g} = 2 - 3 = - 1

, so

K_{p} = K_{c} (RT)^{- 1}

and

K_{c} = K_{p} \cdot RT

RT = 0.0821 \times 800 = 65.68

. Hence

K_{c} = 0.40 \times 65.68 = 26.27 \approx 26 L mo l^{- 1}