Which of the following mixing of 1 M base and 1 M acid leads to the largest increase in temperature?

Which of the following mixing of 1 M base and 1 M acid leads to the largest increase in temperature?
  1. $30 \mathrm{~mL} \mathrm{CH}_3 \mathrm{COOH}$ and 30 mL NaOH
  2. $45 \mathrm{~mL} \mathrm{CH}_3\mathrm{COOH}$ and 25 mL NaOH
  3. 30 mL HCl and 30 mL NaOH
  4. 50 mL HCl and 20 mL NaOH

Solution

The rise in temperature of neutralization reaction will be maximum for maximum number of moles of strong acid and strong base neutralized and lower volume of final solution.
(3) $\mathrm{HCl}+\mathrm{NaOH} \rightarrow \mathrm{NaCl}+\mathrm{H}_2 \mathrm{O}$
mmol $30 \quad 30$
Final volume of solution $=60 \mathrm{~mL}$
Option (1) and (2) have weak acids and in option
(4) only 20 mmol of HCl will be neutralized with 70 mL final volume.

Asked in: JEE Main 2025 (24 Jan Shift 2)

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