is an example of a/an ................ step in a radical chain reaction.
- Ainitiation
- Btermination
- ✓propagation
- Dheterolytic cleavage
is an example of a/an ................ step in a radical chain reaction.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

$O(g) + e^- \to O^-(g); \Delta H = - 142 \,kJ \,mol^{-1}$
$O^-(g) + e \to O^{2-} (g); \Delta H = 844\, kJ \,mol^{-1}$
This is because
$C{O_{\left( g \right)}} + \frac{1}{2}{O_{2\left( g \right)}} \to C{O_{2\left( g \right)}}\,;\,\Delta H = - 300\,kJ$
${H_2}_{\left( g \right)} + \frac{1}{2}{O_2}_{\left( g \right)} \to {H_2}{O_{\left( g \right)}}\,;\,\Delta H = - 250\,kJ$
$C_{(s)} + O_{2(g)} \to CO_{2(g)} ; \Delta H = -x\, kJ$
The value of $x$ will be

$O\left( g \right) + {e^ - } \to O_{\left( g \right)}^ - \,\,\,\,;\,\,\,\,{\Delta _f}{H^\Theta } = - 141\,kJ\,mo{l^{ - 1}}$
${O^ - }\left( g \right) + {e^ - } \to O_{\left( g \right)}^{2 - }\,\,\,\,;\,\,\,\,{\Delta _f}{H^\Theta } = + 780\,kJ\,mo{l^{ - 1}}$
Thus process of formation of $O_2^-$ in gas phase is unfavourable even thought $O_2^-$ is isoelectronic with neon. It is due to the fact that,