Find the enthalpy of dissociation of H2C2O4 from the given data: Enthalpy of neutralisation of strong acid and strong base is -13.7 kcal mol- 1 and that of oxalic acid by a strong base is -25 kcal mol- 1 .

Question

Find the enthalpy of dissociation of H2C2O4 from the given data: Enthalpy of neutralisation of strong acid and strong base is -13.7 kcal mol- 1 and that of oxalic acid by a strong base is -25 kcal mol- 1 . (A) -11.3 kcal mol- 1 (B) 2.4 kcal mol- 1 (C) 1.2 kcal mol- 1 (D) 11.7 kcal mol- 1

Tardigrade Admin · Accepted Answer

One equivalent of oxalic acid gives two moles of

H^{+}

ions, as the basicity of the acid is two.

Now enthalpy of neutralisation is defined for one equivalent of acid as well as base.

For weak acids:

Enthalpy of neutralisation

=

Basicity

\times

enthalpy of neutralisation for strong acid and base

+

enthalpy of dissociation

Thus, enthalpy of dissociation for oxalic acid

= (- 25) - (2 \times - 13.7) = 27.4 - 25 = 2.4 k c a l (m o l)^{- 1}

Q. Find the enthalpy of dissociation of $H_{2} C_{2} O_{4}$ from the given data:

Enthalpy of neutralisation of strong acid and strong base is $- 13.7 k c a l m o l^{- 1}$ and that of oxalic acid by a strong base is $- 25 k c a l m o l^{- 1}$ .

$- 11.3 k c a l m o l^{- 1}$

$2.4 k c a l m o l^{- 1}$

$1.2 k c a l m o l^{- 1}$

$11.7 k c a l m o l^{- 1}$

Q. Find the enthalpy of dissociation of H2​C2​O4​ from the given data: Enthalpy of neutralisation of strong acid and strong base is −13.7kcalmol−1 and that of oxalic acid by a strong base is −25kcalmol−1 .

−11.3kcalmol−1

2.4kcalmol−1

1.2kcalmol−1

11.7kcalmol−1

Q. Find the enthalpy of dissociation of $H_{2} C_{2} O_{4}$ from the given data:

Enthalpy of neutralisation of strong acid and strong base is $- 13.7 k c a l m o l^{- 1}$ and that of oxalic acid by a strong base is $- 25 k c a l m o l^{- 1}$ .

$- 11.3 k c a l m o l^{- 1}$

$2.4 k c a l m o l^{- 1}$

$1.2 k c a l m o l^{- 1}$

$11.7 k c a l m o l^{- 1}$