Problem: Calculate the pH of a 0.40 M solution of sodium acetate (NaCH3COO) given that the Ka of acetic acid (CH3COOH) is 1.8 x 10-5.a. 2.96b. 4.68c. 3.32d. 9.26e. 3.14

FREE Expert Solution

We are being asked to calculate the pH of a 0.40 M solution of sodium acetate (NaCH3COO) given that the Ka of acetic acid (CH3COOH) is 1.8 x 10-5.

NaCH3COO is a salt and it will break up in the solution:

NaCH3COO → Na+(aq) + CH3COO-(aq)

CH3COO- is the conjugate base of a weak acid (CH3COOH):

   CH3COOH    +   H2O(l)    →    CH3COOH-(aq)    +     H3O+(aq)
     (weak acid)                                  (conjugate base)


Since we’re dealing with a weak base, we will have to create an ICE chart to determine the equilibrium concentration of each species:

CH3COO-weak baseproton acceptor
H2O → will act as the weak acidproton donor


Equilibrium reaction:        CH3COO-(aq) + H2O(l)  CH3COOH(aq) + OH-(aq)

View Complete Written Solution
Problem Details

Calculate the pH of a 0.40 M solution of sodium acetate (NaCH3COO) given that the Ka of acetic acid (CH3COOH) is 1.8 x 10-5.

a. 2.96
b. 4.68
c. 3.32
d. 9.26
e. 3.14

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Weak Acids concept. If you need more Weak Acids practice, you can also practice Weak Acids practice problems.