10. Calculate the pH of (a) a 1.7 3 1024 M HCl solution and (b) a 2.3 3 1023 M Ba(OH)2 solution.

11. Calculate the pH of (a) a 0.50 M HCN solution and (b) a 0.050 M HF solution.

12. Determine the pH of an ammonia solution, that is (a) 0.40 M and (b) 0.004 M. ​