Question

Hydrogen ion concentration of an aqueous solution is 1 × 10-4 M. The solution is diluted with equal volume of water. Hydroxyl ion concentration of the resultant solution in terms of p×10-10 mol dm-3 . What is the value of p?

Answer 1

Explanation:
Given:Concentration of H+ ions, [H+] = 1 × 10-4 MThe solution is diluted with an equal volume of water.Hydroxyl ion solution in the resulting solution = p × 10-10 mol dm-3We have to find the value of p.Since, the solution is diluted with an equal volume of water, the concentration of H+ will become one-half of that of the original value. Concentration of [H+] ions = 1×10-42= 0.5 × 10-4 MWhen temperature is 25°C, the ionic product of water , Kw is given as:Kw = [H+] [OH-] = 1 × 10-14 ....... (i)Substituting the value of [H+] in equation (i), we get[0.5 × 10-4] [OH-] = 1 × 10-14[OH-]= 1×10-140.5×10-4= 1×10-100.5= 2 × 10-10 M or 2 × 10-10 mol dm-3Therefore, the value of p = 2.Hence, the correct answer is 2.00.