Is the splitting of water an exothermic or an endothermic process?

One mole of a monatomic ideal gas is taken along two cyclic processes $E \rightarrow F \rightarrow G \rightarrow E$ and $E \rightarrow F \rightarrow H \rightarrow E$ as shown in the $PV$ diagram. The processes involved are purely isochoric,isobaric,isothermal,or adiabatic. Match the paths in List-$I$ with the magnitudes of the work done in List-$II$ and select the correct answer using the codes given below the lists.

List-$I$	List-$II$
$P. \quad G \rightarrow E$	$1. \quad 160 P_0 V_0 \ln 2$
$Q. \quad G \rightarrow H$	$2. \quad 36 P_0 V_0$
$R. \quad F \rightarrow H$	$3. \quad 24 P_0 V_0$
$S. \quad F \rightarrow G$	$4. \quad 31 P_0 V_0$

Codes: $P \quad Q \quad R \quad S$

$A$ given mass of a gas is compressed isothermally until its pressure is doubled. It is then allowed to expand adiabatically until its original volume is restored and its pressure is then found to be $0.75$ of its initial pressure. The ratio of the specific heats of the gas is approximately:

An engine runs between a reservoir at temperature $200 \,K$ and a hot body which is initially at temperature of $600 \,K$. If the hot body cools down to a temperature of $400 \,K$ in the process,then the maximum amount of work that the engine can do (while working in a cycle) is (the heat capacity of the hot body is $1 \,J/K$).

$A$ Carnot cycle for a gas is represented in the pressure-volume $(P-V)$ diagram shown below. Consider the following statements:
$I.$ The area of $ABCD$ is the work done by the gas.
$II.$ The area of $ABCD$ is the total heat absorbed.
$III.$ The change in internal energy of the cycle is zero.
Which of the following is correct?

One mole of a monatomic ideal gas undergoes a cyclic process as shown in the figure (where $V$ is the volume and $T$ is the temperature). Which of the statements below is (are) true?
$(A)$ Process $I$ is an isochoric process
$(B)$ In process $II$,gas absorbs heat
$(C)$ In process $IV$,gas releases heat
$(D)$ Processes $I$ and $III$ are $not$ isobaric