75. Solving a chemistry problem

9. Find the concentration of hydrogen ions and the pH in the following solutions:
a) 0.002 N solution HNO3
b) 0.01 N solution of acetic acid, the degree of dissociation of which in this solution is 4.2%
c) solution of potassium cyanide containing 1 g of this salt in 1 dm3
d) in 0.01 N aqueous solution of ammonia
e) determine [H+] and pH in a mixture of 0.1 N aqueous ammonia solution and 1N ammonium chloride solution