How much $kJ$ energy is released when $6 \ mol$ of octane is burnt in air? Given $\Delta H_f^o$ for $CO_{2(g)}$,$H_2O_{(g)}$ and $C_8H_{18(l)}$ respectively are $-490$,$-240$,and $+160 \ kJ/mol$.

For the reaction,$2Cl_{(g)} \to Cl_{2(g)}$,the signs of $\Delta H$ and $\Delta S$ respectively,are:

The molar heat capacity $(C_p)$ of $CD_2O$ is $10 \, cal \, K^{-1} \, mol^{-1}$ at $1000 \, K$. The change in entropy associated with cooling of $32 \, g$ of $CD_2O$ vapour from $1000 \, K$ to $100 \, K$ at constant pressure will be.....$cal \, deg^{-1}$ ($D = $ deuterium,atomic mass $= 2 \, u$)

Assertion : $\Delta H$ and $\Delta E$ are almost same for the reaction $N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)}$.
Reason : All reactants and products are gases.

Find the enthalpy of neutralisation in $kJ/mol$ for the reaction between $NH_4OH$ and $HCN$ in aqueous solution,given that the enthalpies of ionisation of $NH_4OH$ and $HCN$ are $7 \ kJ/mol$ and $8 \ kJ/mol$ respectively,and the enthalpy of neutralisation of a strong acid and a strong base is $-57.3 \ kJ/mol$.

An organic compound $C_xH_yO_z$ on complete combustion provides equivolume of products $CO_{2(g)}$ and $H_2O_{(g)}$,which is individually double the volume of the organic compound taken. In the process,the volume of oxygen consumed is the same as the volume of $CO_2$ produced,and the liberated heat during combustion is $500 \ kcal/mol$ at constant pressure and $500 \ K$. The formula of the organic compound and $\Delta U$ for the reaction will be: