Thermodynamics

An ideal gas goes through a reversible isothermal expansion (solid line) followed by a reversible adiabatic expansion (dashed line). Which of the following diagram(s) closely depict(s) the entire process?

Consider an exothermic reaction: $2 \mathrm{~A}(\mathrm{~s}) \rightarrow \mathrm{B}(\mathrm{s})+\mathrm{C}(\mathrm{g})+\mathrm{D}(\mathrm{g})$. The correct statement about the reaction is

Consider the following reaction: $\mathrm{CH}_4(\mathrm{~g}) \rightarrow \mathrm{C}(\mathrm{g})+4 \mathrm{H}(\mathrm{g}) ; \Delta_a H^0=1665 \mathrm{kJmol}^{-} 1$ Which of the statements is FALSE?

What is the correct relation between the heat capacity at constant volume $\left(C_v\right)$ and heat capacity at constant pressure $\left(C_p\right)$ for an ideal gas? ( $R=$ Universal gas constant)