Question

1. Which of these solutions will form a buffer?

a. H₂CO₃ and NaHCO₃

b. KF and KCl

c. KOH and KCl

d. HCl and NaOH

3. A solution has [OH^-] of 1.2 x 10^-2. What is the [H₃O⁺] of the solution?

5. Bile has a [OH^-] of 5.6 x 10^-6. What is the pH of bile?

Answer 1

A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa.

a. H₂CO₃ and NaHCO₃

H₂CO₃ is weak acid and NaHCO₃ is a salt of strong base so it acts as a buffer

b. KF and KCl will not a buffer

c. KOH and KCl   will not a buffer

d. HCl and NaOH willnot a buffer

3. Given [OH^-] =1.2 x 10^-2 M

pOH = -log[OH-] = - log(1.2 x 10^-2 ) = 1.92

pH = 14 - pOH = 14-1.92 = 12.08

pH = - log [H3O+] = 12.08

              [H3O+] = 10^-pH

                         = 10^-12.08

                         = 8.32x10^-13M

5.Given [OH^-] = 5.6 x 10^-6.M

pOH = - log[OH-] = - log( 5.6 x 10^-6) = 5.25

pH = 14 - pOH = 8.75