Enthalpy of sublimation of iodine is $24 \ cal \ g^{-1}$ at $200 \ ^oC$. If specific heat of $I_{2(s)}$ and $I_{2(vap)}$ are $0.055$ and $0.031 \ cal \ g^{-1} K^{-1}$ respectively,then enthalpy of sublimation of iodine at $250 \ ^oC$ in $cal \ g^{-1}$ is

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 $+160 \ kJ/mol$.

In a reversible process,under what condition does the heat exchanged become a state function?

The molar heat capacity for an ideal gas at constant pressure is $20.785 \ J \ K^{-1} \ mol^{-1}$. The change in internal energy is $5000 \ J$ upon heating it from $300 \ K$ to $500 \ K$. The number of moles of the gas is [Nearest integer] (Given: $R = 8.314 \ J \ K^{-1} \ mol^{-1}$)

For the following reaction occurring in automobiles,the values of $\Delta H, \Delta S, \text{and } \Delta G$ are respectively:
$2C_8H_{18(g)} + 25O_2(g) \rightarrow 16CO_2(g) + 18H_2O(g)$

$7 \ g$ of $N_{2(g)}$ at $27 \ ^oC$ is expanded reversibly and isothermally from an initial pressure of $0.5 \ MPa$ to a final pressure of $0.1 \ MPa$. Determine the approximate work done $[ln \ 5 = 1.6]$ ..... $J$