The heat of neutralization of HCl by NaOH is -55.9 kJ mol-1 and that of HCN is -12.1 kJ; the energy of dissociation of HCN is

Question

The heat of neutralization of HCl by NaOH is -55.9 kJ mol-1 and that of HCN is -12.1 kJ; the energy of dissociation of HCN is (A) 43.8 kJ (B) -43.8 kJ (C) -68 kJ (D) 68 kJ

Tardigrade Admin · Accepted Answer

H++OH- xrightarrow[]H2O;Δ H=-55.9kJ ?(i) HCN+OH-→ H2O+CN-;Δ H=-12.1 kJ ?(ii) On revers Eq. (i) and then adding to Eq. (ii), we get HCN xrightarrow[]H++CN-;Δ H=+43.8kJ

Q. The heat of neutralization of HCl by NaOH is $- 55.9 k J m o l^{- 1}$ and that of HCN is -12.1 kJ; the energy of dissociation of HCN is

43.8 kJ

-43.8 kJ

-68 kJ

68 kJ

$H^{+} + O H^{-} H_{2} O; Δ H = - 55.9 k J$ ?(i) $H CN + O H^{-} \to H_{2} O + C N^{-}; Δ H = - 12.1 k J$ ?(ii) On revers Eq. (i) and then adding to Eq. (ii), we get $H CN H^{+} + C N^{-}; Δ H = + 43.8 k J$

Q. The heat of neutralization of HCl by NaOH is −55.9kJmol−1 and that of HCN is -12.1 kJ; the energy of dissociation of HCN is