Will the addition of NaC2H3O2 to a CH3COOH solution cause the pH to increase or decrease? Explain.

pH will be increased.

Explanation:

When you mixed sodium acetate and acetic acid,  pH will be maintained and will have slight changes. This constitutes what is known as a buffer solution.

But if you analize the reactions:

First of all, you have a weak acid, acetic:

CH₃COOH   +  H₂O  ⇄  CH₃COO⁻  +   H₃O⁺      Ka

And the salt can be dissociated as:

NaCH₃COO →  CH₃COO⁻  +   Na⁺

As you are adding acetate, this is the conjugate strong base from the weak acid and as every base, it brings hydroxides to medium, so the pH will be increased. Protons from the acid will be neutralized, thouhgh.

CH₃COO⁻  +   H₂O  ⇄  CH₃COOH + OH⁻     Kb

the answer to your question is c.

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