Question

Which of the following relations between the reactions and equilibrium constant for a general reaction, $aA+bB\rightleftharpoons cC+dD$ is not correct?

• A. $aA+bB\rightleftharpoons cC+dD:K_c$
• B. $cC+dD\rightleftharpoons aA+bB:K_c^{\prime }=\frac{1}{K_c}$
• C. $naA+nbB\rightleftharpoons ncC+ndD:K_c^{\prime \prime }=K_c^n$
• D. $aA+bB\rightleftharpoons cC+dD:K_c=K_p$

Answer 1

The correct option is D $aA+bB\rightleftharpoons cC+dD:K_c=K_p$

Kc and Kp are the equilibrium constants of gaseous mixtures. However, the difference between the two constants is that Kc is defined by molar concentrations, whereas Kp is defined by the partial pressures of the gasses inside a closed system. Kc and Kp depend on the values of a,b,c,d.

$K_p=K_c(RT{)}^{\Delta n}$

$K_c=\frac{K_p}{{RT}^{\Delta n}}$

Where $\Delta n=(c+d)-(a+b)$ i.e. number of moles of gaseous products – number of moles of gaseous reactants in the balanced chemical reaction.