Ka and Kb of compounds

Example #1: Associated with any weak acid or weak base is a K_a or K_b value respectively. 

Example #2: Consider two aqueous solutions of equal concentration. Which statement is true?

chlorous acid (HClO₂, K_a = 1.1 x10 ^-2 ) and phenol (HC₆H₅O, K_a = 1.3 x10 ^-10)

a) HClO₂ produces more [H₃O⁺] than HC₆H₅O

b) HClO₂ is basic compared with HC₆H₅O

c) HClO₂ produces less [H₃O⁺ ] than HC₆H₅O

d) HClO₂ is a strong acid

e) ClO₂^– produces more [OH⁻] than C₆H₅O^–

Example #3: Which of the following compounds has the strongest conjugate acid?

a) C₂H₅NH₂        (K_b = 5.6 x 10^-4)

b) H₂NNH­₂         (K_b =  1.3 x 10^-6)

c)  NH₃               (K_b =  1.75 x 10^-5)

d)  HONH­₂          (K_b = 1.1 x 10^-8)

Example #4: At 0 ^oC, the ion product constant of water is 1.2x10^–15. The pH of pure water at this temperature is:

a) 6.88

b) 7.00

c) 7.46

d) 7.56