Question

When sodium acetate is added to acetic acid, it:

• A. increases ionisation of acetic acid
• B. decreases ionisation of acetic acid
• C. increases ionisation of sodium acetate
• D. independent of concentration

Answer 1

The Correct Option is B

Sodium acetate is a strong electrolyte and it has an ion $ (C{{H}_{3}}CO{{O}^{-}}) $ common with weak $ C{{H}_{3}}COOH $ . Hence, it decrease the ionisation of $ C{{H}_{3}}COOH $ due to common ion effect.

Answer 2

The pH is a quantity that describes the chemical condition of a substance in nature. It gives us the extent of acidity and basicity of a substance. It also determines the behavior and properties of the substance and its applications and reactivity. The acidity and basicity of a substance are determined based on a scale that ranges from 

0−14 in which if the pH of a substance ranges below the value of 7, then the substance is said to be acidic in nature, and if it ranges more than 7, then it is said to be basic and has a value equal to 7 on the pH scale determines that the substance is neutral in nature. That is it is neither an acid nor a base like water. So, if the concentration of the H⁺ ions decreases, then the pH value also decreases which means it is acidic in nature, and if the concentration of the H⁺ ions increases then the pH value also increases and thus, it is basic in nature.

For the above question,

CH₃COONa is obtained from the reaction of NaOH and CH₃COOH Thus, when 

CH₃COONa ionizes forms. 

CH₃COONa→CH₃COO⁻+Na⁺

When sodium acetate is added to a solution of acetic acid the concentration of 

H⁺ ions decrease as the concentration of salt increases in the buffer solution and thus, the value of pH increases.

 

So, the correct option is (B).