Question

The equilibrium expression for a reaction is Keq=[H+]6[Bi2+]2[H2S]3. Which of the following could be the reaction? A. 6H+(aq) + BiS(s) 2Bi2+(aq) + 3H2S(g) B. 2Bi2+(aq) + 3H2S(aq) Bi2S3(s) + 6H+(aq) C. 6H+(aq) + Bi2S3(s) 2Bi2+(aq) + 3H2S(g) D. 2Bi2+(aq) + 3H2S(aq) Bi2S3(aq) + 6H+(aq)

Answer 1

So the question ask to calculate the equilibrium and ask on which of the following choices is the possible reaction and based on my calculation and the use of the formula i came up with an answer of letter B. I hope you are satisfied with my answer and feel free to ask for more. 

Answer 2

Answer : The correct reaction is, (B) $2Bi^{2+}(aq)+3H_2S(g)\rightleftharpoons Bi_2S_3(s)+6H^+(aq)$

Explanation :

The equilibrium expression for the reaction is determined by multiplying the concentrations of products and divided by the concentrations of the reactants and each concentration is raised to the power that is equal to the coefficient in the balanced reaction.

As we know that the concentrations of pure solids are constant that is they do not change. Thus, they are not included in the equilibrium expression.

(a) The given balanced chemical reaction is,

$6H^+(aq)+BiS(s)\rightleftharpoons 2Bi^{2+}(aq)+3H_2S(g)$

So, the equilibrium constant expression will be,

$k_{eq}=\frac{[Bi^{2+}]^2[H_2S]^3}{[H^+]^6}$

(b) The given balanced chemical reaction is,

$2Bi^{2+}(aq)+3H_2S(g)\rightleftharpoons Bi_2S_3(s)+6H^+(aq)$

So, the equilibrium constant expression will be,

$k_{eq}=\frac{[H^{+}]^6}{[Bi^{2+}]^2[H_2S]^3}$

(c) The given balanced chemical reaction is,

$6H^+(aq)+Bi_2S_3(s)\rightleftharpoons 2Bi^{2+}(aq)+3H_2S(g)$

So, the equilibrium constant expression will be,

$k_{eq}=\frac{[Bi^{2+}]^2[H_2S]^3}{[H^{+}]^6}$

(d) The given balanced chemical reaction is,

$2Bi^{2+}(aq)+3H_2S(g)\rightleftharpoons Bi_2S_3(aq)+6H^+(aq)$

So, the equilibrium constant expression will be,

$k_{eq}=\frac{[H^{+}]^6[Bi_2S_3]}{[Bi^{2+}]^2[H_2S]^3}$

Hence, the correct reaction is, (B) $2Bi^{2+}(aq)+3H_2S(g)\rightleftharpoons Bi_2S_3(s)+6H^+(aq)$