Question

During titration of acetic acid with aq.$NaOH$ solution, the neutralisation graph has a vertical line. This line indicates.

• A. alkaline nature of equivalence
• B. acidic nature of equivalence
• C. neutral nature of equivalence
• D. depends on experimental proceeding

Answer 1

Answer: (A)

alkaline nature of equivalence

In the titration of a weak acid (${CH}_{3}COOH$) with a strong base ($NaOH$), there is a change in the $pH$ value at the end point. But it is not sharp due to weak ionisation of ${CH}_{3}COOH$. Due to the excess of free base beyond the equivalence point, there is a steep rise in $pH$ which is indicated by the vertical line.

Hence, the vertical line in the graph indicates alkaline nature of equivalence.