Question

In which case mixing of a strong acid and a strong base each of $1$N concentration, temperature increase is highest?

• A. $20$ml acid - $30$ ml alkali
• B. $40$ ml acid - $40$ ml alkali
• C. $25$ ml acid - $25$ ml alkali
• D. $35$ ml acid - $15$ ml alkali

Answer 1

The correct option is B $40$ ml acid - $40$ ml alkali

More amount of acid reacts with an equal amount of base, higher the amount of energy or heat releases.
(a) 20ml acid-30ml alkali: In this case, 20ml of acid reacts with 20ml of the base, (10ml base is present in excess).

(b) 40ml acid-40ml alkali: In this case, 40ml of acid reacts with 40ml of the base.

(c) 25ml acid-25ml alkali: In this case, 25ml of acid reacts with 25ml of the base.

(d) 35ml acid-15ml alkali: In this case, 15ml of acid reacts with 15ml of the base, ( 20ml acid is present in excess).
so increases the order of release in heat
d < a < c < b

Hence (B) is the Answer