Which one among the following is the correct option for the relationship between $C_{P}$ and $C_{V}$ for one mole of an ideal gas?

According to thermodynamics,when can a process be called reversible?

When $5 \ mol$ of $He$ gas expand isothermally and reversibly at $300 \ K$ from $10 \ L$ to $20 \ L,$ the magnitude of the maximum work obtained is $....... \ J$. [nearest integer] (Given: $R = 8.3 \ J \ K^{-1} \ mol^{-1}$ and $\log 2 = 0.3010$)

Calculate the work done during compression of $2 \ mol$ of an ideal gas from a volume of $1 \ m^3$ to $10 \ dm^3$ at $300 \ K$ against a constant external pressure of $100 \ kPa.$

For the process to occur under adiabatic conditions,the correct condition is:

In an endothermic reaction,the value of $\Delta H$ is