Question

2 a, b and c

Experiment 22 Properties of Systems in Chemical Equilbrium-Le Chatelier's Principle Magnesium hydroxide is only very slighly soluble in water. The reaction by which it goes into solution is: Mg(OH),6)Mg (a)+20H (ag) a. Formulate the expression for the equilibrium constant, Kr for the above reaction. b. It is possible to dissolve significant amounts of Mg(OH), in solutions in which the concentration of or OH is kept very, very small. Explain, using Kg why this is the case. either Mg c. Explain why MgrOH), might have very appreciable solubility in 1 M HCI. (Hint: Consider the effect of Reaction 3 on the Mg(OH), solution reaction.)

Answer 1

Mg (OH)_2 doubleheadarrow mg^2 + (aq) + 2 OH^- (aq) ksp = [mg^2 +] [OH^-]^2/[MG(oh)_2] as given mg(OH)_2 is solid phase it concentration is taken as almost constant ksp = [mg^2 +] [OH^-]^2 MG (OH)_2 doubleheadarrow mg^2 + + 2 (OH)^- in the presence of mg^2 + (or) OH^- the reaction moves to left sides to increase of reactance so solubility decrease than ksp decrease we are having OH^- in the products H^+ + OH^- rightarrow H_2 O According to principle to maintain kc reaction shifts towards right side easily soluble ksp increases