$\Delta {H_f} = - 46.0\,kJ/mol$
$H + H \leftrightarrow {H_2};\,\Delta {H_f} = - 436\,kJ/mol$
$N + N \leftrightarrow {N_2};\,\Delta {H_f} = - 712\,kJ/mol$
$\Delta {H_f}(N{H_3}) = \frac{1}{2}\Delta {H_{N - N}} + \frac{3}{2}\Delta {H_{H - H}} - \Delta {H_{N - H}}$
$ - 46 = \frac{1}{2}( - 712) + \frac{3}{2}( - 436) - \Delta {H_{N - H}}$
On calculation
$\Delta {H_{N - H}} = - 964\,kJ/mol$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
| $A$ | $B$ | $C$ | |
| $IE_1$ | $400$ | $550$ | $1150$ |
| $IE_2$ | $2650$ | $1070$ | $2090$ |
Identify the element which represent a nonmetal.
Codes: $ \quad P \quad Q \quad R \quad S$
