Question

The concentration of hydroxyl ion in solution left after mixing 100 mL of 0.1 M MgCl₂ and 100 mL of 0.2 M NaOH (K_sp of Mg(OH)₂ = 1.2 x 10^–11] is 

 (a) 2.8 x 10^–3 

(b) 2.8 x 10^–2 

(c) 2.8 x 10^–4 

(d) 2.8 x 10^–5. 

Answer 1

Find S then [OH^-] = 2S which is 2.8 x 10^-4.