Question

When a 0.20 M solution of acetic acid is neutralized with 0.20 M NaOH in 0.50 L of water the pH of
resulting solution will be (Given: PK for CH,COOH=4.74)​

Answer 1

Given:

• The concentration of acetic acid and NaOH is 0.20M
• The volume of the solution is 0.50L
• PKa of acetic acid is 4.74.

To find:

The pH of the resulting solution.

Solution:

• The concentration of the sodium acetate formed will also be equal to 0.20M
• Sodium acetate is a salt of strong base and weak acid.
• For, a salt of strong base and weak acid, the formula for the pH of the solution at room temperature is given by pH = 7 + (pKa - logC)/2 , where C is the concentration of the salt.
• pH = 7+ (4.74 - log(0.2))/2 = 9.70

Answer:

The pH of the resulting solution is equal to 9.70