Question

The, heat of neutralization of HCL by NaOH is -55.9 Kilo joule per mole. if the heat of neutralization of hcn by NaOH is -12.1 Kilo joule per mole the energy of dissociation of hcn is

Answer 1

Explanation:

HCl + NaOH -----> NaCl+H2O ∆H = -55.9KJ/mol

NaCl+ H2O -----> NaOH+ HCl ∆H =55.9KJ/mol ---------------(1)

HCN + NaOH ---------> NaCH+H2O ∆H = -12.1KJ/mol ---------(2)

Adding (1) and (2).

HCN + NaCl -------> NaCN+ HCl ------> ∆H =55.9-12.1

43.8KJ/mol

Therefore, Energy of dissociation for one mole of HCN is 43.8 KJ.

Answer 2

Explanation:

HCl + NaOH -----> NaCl + H2O ∆H = -55.9KJ/mol.

NaCl + H2O ------> NaOH + HCl ∆H = 55.9 KJ/mol............ (i)

HCN + NaOH -----> H2O ∆H = -12.1 KJ/mol................... (ii)

Adding (i) and (ii)

HCN + NaCl ------> NaCN + HCl -----> ∆H = 55.9 - 12.1 = 43.8 KJ/mol.

Therefore, The Energy of dissociation for one mol of HCN is 43.8 KJ.