Question

Consider the following reaction where K. = 154 at 298 K. 2NO(g) + Br2(g) 2 2NOBr(g) A reaction mixture was found to contain 5.19x10-2 moles of NO(g), 3.85x10 - moles of Br (9) and 9.56x102 moles of NOBr(g). in a 1.00 liter container. Is the reaction at equilibrium? If not, what direction must it run in order to reach equilibrium? The reaction quotient, Qc equals The reaction A. must run in the forward direction to reach equilibrium. B. must run in the reverse direction to reach equilibrium. C. is at equilibrium.

Answer 1

Answer:

The correct option is A.

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_{eq}$

K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.

$2NO(g) + Br_2(g)\rightleftharpoons 2NOBr(g)$

The equilibrium constant of the reaction = $K_c=154$

Concentration of NO gas = $[NO]=\frac{5.19\times 10^{-2} mol}{1L}=5.19\times 10^{-2} M$

Concentration of bromine gas = $[Br_2]=\frac{3.85\times 10^{-2} mol}{1L}=3.85\times 10^{-2} M$

Concentration of NOBr gas = $[NOBr]=\frac{9.56\times 10^{-2} mol}{1L}=9.56\times 10^{-2} M$

$Q_c=\frac{[NOBr]^2}{[NO]^2[Br]}$

$Q_c=\frac{(9.56\times 10^{-2} M)^2}{(5.19\times 10^{-2})^2\times 3.85\times 10^{-2} M}=88.13$

$K_c>Q_c$

No , the reaction is not at equilibrium. the reaction will move in forward direction to attain an equilibrium.