Question

What is the [OH^-] in a 0.0018 M HCl soltuion? Please show calculations.

a.) 5.6 x 10^-12 M

b.) 11.2 x 10^-12 M

c.) 0.0009 M

d.) 1.0 x 10^-12 M

e.) 0.0018 M

Answer 1

The ionic product of water Kw = 1.0 x 10^-14 is the product of ionic cncentrations [H⁺] and [OH^-].

The Kw being an equilibrium constant does not vary with initial concentrations of [H⁺] and [OH^-] but varies with temperature only.

Thus even in an acidic solution, the ionic product oof water remains same.

Given [H⁺] = 0.0018M in the HCl solution. then [OH^-] = Kw/[H⁺]

      Thus [OH^-] = 1.0 x 10^-14/0.0018 =5.55 x 10^-12M

thus the option 'a' is correct