The standard molar enthalpies of formation for ethane,$CO_2$,and water $(l)$ are $-21.1$,$-94.1$,and $-68.3 \text{ kcal/mol}$ respectively. What is the standard molar enthalpy of combustion for ethane in $\text{kcal/mol}$?

At the temperature $T$ $(K)$ for the reaction: $X_2O_{4(l)} \rightarrow 2XO_{2(g)}$,given $\Delta U = x \ kJ \ mol^{-1}$ and $\Delta S = y \ J \ K^{-1} \ mol^{-1}$. The Gibbs energy change for the reaction is: (Assume $X_2O_4$ and $XO_2$ are ideal gases)

For the reaction $2X_{(s)} + 2Y_{(s)} \to 2C_{(\ell)} + D_{(g)}$,the value of $q_p$ is $-28 \, \text{kcal mol}^{-1}$ at $2700 \, ^\circ\text{C}$. Calculate the value of $q_v$ in $\text{kcal mol}^{-1}$.

At $25^{\circ} C$,$50 \ g$ of iron reacts with $HCl$ to form $FeCl_2$. The evolved hydrogen gas expands against a constant pressure of $1 \ bar$. The work done by the gas during this expansion is ....... $J$. (Round off to the Nearest Integer) [Given : $R = 8.314 \ J \ mol^{-1} \ K^{-1}$. Assume,hydrogen is an ideal gas] [Atomic mass of $Fe$ is $55.85 \ u$]

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If $T_i$ is the initial temperature and $T_f$ is the final temperature,which of the following statements is correct?

At $300 \ K$,$3.0 \ \text{moles}$ of an ideal gas at $3.0 \ \text{atm}$ pressure is compressed isothermally to one half of its volume by an external pressure of $6.0 \ \text{atm}$. The work done (in $kJ$) is. Given,$R=0.082 \ \text{L atm K}^{-1} \text{mol}^{-1}$ $(1 \ \text{L atm} = 101.3 \ \text{J})$.