The molar solubility of Zn(OH)₂ in 0.1 M NaOH solution is x $$\times$$ 10^$$-$$18 M. The value of x is _________ (Nearest integer)

(Given : The solubility product of Zn(OH)₂ is 2 $$\times$$ 10^$$-$$20)

The pH of a solution obtained by mixing 50 mL of 1 M HCl and 30 mL of 1 M NaOH is x $$\times$$ 10^$$-$$4. The value of x is ____________. (Nearest integer) [log 2.5 = 0.3979]

A₃B₂ is a sparingly soluble salt of molar mass M (g mol^$$-$$1) and solubility x g L^$$-$$1. The solubility product satisfies $${K_{sp}} = a{\left( {{x \over M}} \right)^5}$$. The value of a is _____________. (Integer answer)

The solubility of CdSO₄ in water is 8.0 $$\times$$ 10^$$-$$4 mol L^$$-$$1. Its solubility in 0.01 M H₂SO₄ solution is __________ $$\times$$ 10^$$-$$6 mol L^$$-$$1. (Round off to the Nearest Integer). (Assume that solubility is much less than 0.01 M)