Equal volumes of methanoic acid and sodium hydroxide are mixed, if x is the heat of formation of water, then heat evolved on neutralisation is

Options

(a) twice of x
(b) equal to x
(c) more than x
(d) less than x

Correct Answer:

less than x

Explanation:

“Methanoic acid(HCOOH), Sodium hydroxide(NaOH). Weak acid and strong base neutralisation. H⁺ + OH⁻ → H₂O + x(Heat of formation),
HCOOH ⇌ HCOO⁻ + H⁺, NaOH ⇌ Na⁺ + OH⁻,
H⁺ + OH⁻ ⇌ H₂O + Less than x (Heat of reaction). Because, some of the energy is lost in ionization of weak acid, HCOOH.”.