The heat of combustion $\left(kJ \ mol^{-1}\right)$ is highest for

$A$ gas present in a cylinder expands against a constant pressure of $1 \, atm$ from a volume of $2 \, L$ to a volume of $6 \, L$. In doing so,it absorbs $800 \, J$ of heat from the surroundings. The change in internal energy of the process is ....... $J$.

State $1 \longleftarrow$ State $2 \longleftarrow$ State $3$
$\left(\begin{array}{c} T=300 \ K \\ P=15 \ bar \\ 1 \ mole \end{array}\right) \left(\begin{array}{c} T=300 \ K \\ P=10 \ bar \\ 1 \ mole \end{array}\right) \left(\begin{array}{c} T=300 \ K \\ P=5 \ bar \\ 1 \ mole \end{array}\right)$
The above shows a cyclic process. Calculate the total work done during one complete cycle. (Assume a single step to reach the next state).

For a spontaneous process,the correct statement$(s)$ is (are):

Five moles of a gas are subjected to a series of changes as shown in the given graph. What are the processes $A \rightarrow B$,$B \rightarrow C$,and $C \rightarrow A$ respectively?

Match the following terms in Column-$I$ with their corresponding descriptions in Column-$II$:

Column-$I$	Column-$II$
$(a)$ Adiabatic process	$(1)$ Heat
$(b)$ Isolated system	$(2)$ At constant volume
$(c)$ Isothermal change	$(3)$ First law of thermodynamics
$(d)$ Path function	$(4)$ No exchange of matter and energy
$(e)$ State function	$(5)$ No heat exchange
$(f)$ $\Delta U = q$	$(6)$ Constant temperature
$(g)$ Law of conservation of energy	$(7)$ Internal energy
$(h)$ Reversible process	$(8)$ $p_{ext} = 0$
$(i)$ Free expansion	$(9)$ At constant pressure
$(j)$ $\Delta H = q$	$(10)$ Infinitely slow process involving multiple equilibrium states
$(k)$ Intensive property	$(11)$ Entropy
$(l)$ Extensive property	$(12)$ Pressure,$(13)$ Specific heat