At constant $T$ and $P$,which one of the following statements is correct for the reaction,$CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)}$?

An ideal gas is subjected to a cyclic process involving four thermodynamic states. The amounts of heat $(Q)$ and work $(W)$ involved in each of these processes are:
$Q_1 = 6000 \, J, Q_2 = -5500 \, J, Q_3 = -3000 \, J, Q_4 = 3500 \, J$
$W_1 = 2500 \, J, W_2 = -1000 \, J, W_3 = -1200 \, J, W_4 = x \, J$
The ratio of the net work done by the gas to the total heat absorbed by the gas is $\eta$. The values of $|x|$ and $\eta$ respectively are:

What is the amount of work done when $0.5 \ mol$ of methane,$CH_{4(g)}$,is subjected to combustion at $300 \ K$? (Given: $R = 8.314 \ J \ K^{-1} \ mol^{-1}$)

For the reaction $C_3H_8(g) + 5O_2(g) \rightarrow 3CO_2(g) + 4H_2O(l)$,the value of $\Delta H - \Delta U$ is:

$(\Delta H - \Delta U)$ for the formation of carbon monoxide $(CO)$ from its elements at $298 \ K$ is ............. $J \ mol^{-1}$. $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$

Three moles of an ideal gas are compressed isothermally from $60 \ L$ to $20 \ L$ using a constant external pressure of $5 \ atm$. The heat exchange $Q$ for the compression is $....... \ L \cdot atm$.