question_answer 152)

    How will you predict the following stages of a reaction by comparing the value of \[{{K}_{c}}\]and \[{{Q}_{c}}\] ? (i) Net reaction proceeds in forward direction (ii) Net reaction proceeds in backward direction (iii) No net reaction occurs

Answer:

  Let us consider the reaction \[A+B\underset{{}}{\leftrightarrows}C+D\] Reaction Quotient \[{{Q}_{c}}=\frac{[C][D]}{[A][B]}\] (I) When \[{{Q}_{c}}<{{K}_{c}}\] then reaction will proceed in forward direction to increase the value of \[{{Q}_{c}},\]i.e., to attain equilibrium. (ii) When \[{{Q}_{c}}>{{K}_{c}}\] then reaction will be fast in backward direction, i.e., it will proceed in backward direction to decrease the value of \[{{Q}_{c}}\] (iii) When\[{{Q}_{c}}={{K}_{c}}\], the reaction is at equilibrium, i.e., there is no net reaction.