Solid NaHCO3 decomposes in an evacuated vessel at 400 K: 2NaHCO3(s) Na2CO3(s) + H2O(g) + CO2(g). At equilibrium the total pressure is 1.60 atm. Use R = 0.0821 L atm mol^-1 K^-1. Which statements are correct?

K_c approx 5.9x10^-4 mol^2 L^-2

Adding more solid NaHCO3 at constant volume raises the total pressure

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ce109

Solid $NaHCO X_{3}$ decomposes in an evacuated vessel at 400 K: $2 NaHCO X_{3} (s) Na X_{2} CO X_{3} (s) + H X_{2} O (g) + CO X_{2} (g)$ . At equilibrium the total pressure is 1.60 atm. Use $R = 0.0821 L atm mo l^{- 1} K^{- 1}$ . Which statements are correct?

The two gases are formed in equal amounts, so

p_{H X_{2} O} = p_{CO X_{2}} = 0.80

atm and

K_{p} = 0.8 0^{2} = 0.64 at m^{2}

(not

1.6 0^{2}

Δ n = 2

, so

K_{c} = K_{p} / (RT)^{2} = 0.64/ (32.84)^{2} = 5.93 \times 1 0^{- 4} mo l^{2} L^{- 2}

. Pure solids do not affect the pressure. Statements 1 and 2 are correct.