Chapter 15.2, Problem 1PPA

Write the reaction quotient for each of the following reactions.

$\begin{array}{l}\left(\text{a}\right){\text{2N}}_{\text{2}}\text{O}\left(g\right)\rightleftarrows {\text{2N}}_{\text{2}}\left(g\right)+{\text{O}}_{\text{2}}\left(g\right)\\ \left(\text{b}\right)\text{2NOBr}\left(g\right)\rightleftarrows \text{2NO}\left(g\right)+{\text{Br}}_{\text{2}}\left(g\right)\\ \left(\text{c}\right)\text{HF}\left(aq\right)\rightleftarrows {\text{H}}^{\text{+}}\left(aq\right)+{\text{F}}^{\text{-}}\left(aq\right)\\ \left(\text{d}\right)\text{CO}\left(g\right)+{\text{H}}_{\text{2}}\text{O}\left(g\right)\rightleftarrows {\text{CO}}_{\text{2}}\left(g\right)+{\text{H}}_{\text{2}}\left(g\right)\\ \left(\text{e}\right){\text{CH}}_{\text{4}}\left(g\right)+{\text{2H}}_{\text{2}}\text{S}\left(g\right)\rightleftarrows {\text{CS}}_{\text{2}}\left(g\right)+{\text{4H}}_{\text{2}}\left(g\right)\\ \left(\text{f}\right){\text{H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\left(aq\right)\rightleftarrows {\text{2H}}^{\text{+}}\left(aq\right)+{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}^{\text{2-}}\left(aq\right)\end{array}$

Interpretation Introduction

Interpretation

To drive the reaction quotient (Qc) given the equilibrium reactions.

Concept Introduction:

Reaction quotient: This type of chemical equilibrium reaction proceeds likely to produced, given either the pressure (or) the concentration of the reactants and the products. The value can be compared to the equilibrium constant, to determine the direction of the reaction that is take place. Then reaction quotient (Qc) the indication of Q can be used to determine which direction will shift to reach of chemical equilibrium process.

Balancing of equilibrium reaction: The many of chemical reaction involving for, reversible reaction is occurring backwards and forwards at the time by the same amount, it is balancing point of a chemical reaction, it seems to stop happening when the rates are equal equilibrium has occurred.

Answer to Problem 1PPA

The reaction quotients (Qc) for given the different equilibrium reactions (a-f) are shown below

$\begin{array}{l}(a).Qc=\frac{{[N_2]}^2[O_2]}{{[N_{2}O]}^2}(b).Qc=\frac{{[NO]}^2[B{r}_2]}{{[NOBr]}^2}(c).Qc=\frac{[H^{+}][F^{-}]}{[Ag]{[N{H}_3]}^2}\\ (d).Qc=\frac{[C{O}_2][H_2]}{[CO][H_{2}O]}(e).Qc=\frac{[C{S}_2]{[H_2]}^4}{[C{H}_4]{[H_{2}O]}^2}(f).Qc=\frac{[H^{+}][C_2{O}_4^{2-}]}{[H_2{C}_2{O}_4]}\end{array}$

Explanation of Solution

To find: The reaction quotient should be solved given the equilibrium reactions.

Write and analyze the reaction quotient (Qc) fallowing reactions.

$\begin{array}{l}(a).2{\text{N}}_{\text{2}}\text{O}(g)\rightleftharpoons {\text{2N}}_{\text{2}}(g)+{\text{O}}_{\text{2}}(g)(b).\text{2NOBr}(g)\rightleftharpoons \text{2NO}(g)+{\text{Br}}_{\text{2}}\text{(g)}\\ Qc=\frac{{[N_2]}^2[O_2]}{{[N_{2}O]}^2}Qc=\frac{{[NO]}^2[B{r}_2]}{{[NOBr]}^2}\\ (c).HF(aq)\rightleftharpoons H^{+}(aq)+F^{-}(aq)(d).CO(g)+H_{2}O(g)\rightleftharpoons C{S}_2(g)+4H_2(g)\\ Qc=\frac{[H^{+}][F^{-}]}{[Ag]{[N{H}_3]}^2}Qc=\frac{[C{O}_2][H_2]}{[CO][H_{2}O]}\\ (e).C{H}_4(g)+2H2S(g)\rightleftharpoons C{S}_2(g)+4H_2(g)(f).H_2{C}_2{O}_4\rightleftharpoons {\text{2H}}^{\text{+}}(aq)+C2O{4}_4^{2-}(aq)\\ Qc=\frac{[C{S}_2]{[H_2]}^4}{[C{H}_4]{[H_{2}O]}^2}(f).Qc=\frac{[H^{+}][C_2{O}_4^{2-}]}{[H_2{C}_2{O}_4]}\\ \end{array}$

The (Qc) equation is written by multiplying the activities for the species of the products and dividing by the activities of the reactants. If any component in the reaction has a coefficient, indicated above with lower case letters, the concentration is raised to the power of the coefficient.  The compare for the given above equation (1 & 2) and should solved above. Furthermore the Qc changes as the reaction progress and is only equal to the equilibrium constant when total system is at same equilibrium.

Conclusion

The reaction quotients (Qc) has solved given the equilibrium reactions.