At 400 K the equilibrium constant for the gas-phase reaction is 4.0

CHEMISTRY · Single correct · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)

Problem

At 400 K the equilibrium constant

K_p

for the gas-phase reaction

2\,\text{A}(g) \;\rightleftharpoons\; \text{B}(g) + \text{C}(g)

is 4.0. A sealed container initially contains 1.0 atm of A, 1.0 atm of B, and no C. Which of the following best describes how the partial pressures change as the system moves toward equilibrium? (a)

p_\text{A}

increases,

p_\text{B}

decreases, and

p_\text{C}

decreases (b)

p_\text{A}

decreases,

p_\text{B}

decreases, and

p_\text{C}

increases (c)

p_\text{A}

decreases, while

p_\text{B}

and

p_\text{C}

both increase (d)

p_\text{A}

decreases,

p_\text{B}

increases, and

p_\text{C}

\;\text{remains essentially unchanged}

Related theory

Chemical Equilibrium
Equilibrium
Equilibrium constant calculations
Equilibrium Constant

Browse the problem library