4. Chemical bonding and molecular structure — Chemistry STD 11 Science — Question

Given that

Salt            ||         $K_{sp}$

$AgCl$        ||        $2 \times {10^{ - 10}}$

$AgBr$       ||       $5 \times {10^{ - 13}}$

$Ag$           ||        $9 \times {10^{ - 17}}$

$O\left( g \right) + {e^ - } \to O_{\left( g \right)}^ - \,\,\,\,;\,\,\,\,{\Delta _f}{H^\Theta } =  - 141\,kJ\,mo{l^{ - 1}}$

${O^ - }\left( g \right) + {e^ - } \to O_{\left( g \right)}^{2 - }\,\,\,\,;\,\,\,\,{\Delta _f}{H^\Theta } =  + 780\,kJ\,mo{l^{ - 1}}$

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,

${C_6}{H_6}\left( l \right) + \frac{{15}}{2}{O_2}\left( g \right) \longrightarrow 6C{O_2}\left( g \right) + 3{H_2}O\left( l \right)\,;\,\Delta H =  - 3271\,kJ$

What is $\Delta U$ for the combustion of $1.5\, mole$ of benzene at $27\,^oC$. .....$ kJ$