Question

The two equilibria, AB(aq) A+(aq) + B-(aq) and AB(aq) + B-(aq) AB2-(aq) are simultaneously maintained in a solution with equilibrium constants, K1 and K2 respectively. The ratio of concentration of A+ to AB2- in the solution is :

• A. Directly proportional to the concentration of B– (aq.).
• B. Inversely proportional to the concentration of B– (aq.).
• C. Directly proportional to the square of the concentration of B– (aq.).
• D. Inversely proportional to the square of the concentration of B– (aq.).

Answer 1

Answer: (D)

Inversely proportional to the square of the concentration of B– (aq.).

Answer 2

AB $\rightleftharpoons$ A+ + B– AB + B– $\rightleftharpoons$ AB2–

$\mathrm { K } _ { 1 } = \frac { \left. \mathrm { A } ^ { + } \right] \mathrm { B } ^ { - } } { [ \mathrm { AB } ] }$

Therefore, (4) option is correct.