$V_0$ and $V_t$ are volumes of an ideal gas at $0\ ^\circ\text{C}$ and $t\ ^\circ\text{C}$ respectively, find ratio $\dfrac{V_t}{V_0}$

Which of the following equations is used to obtain enthalpy change of a reaction?

A system is provided 50 J of heat and work done on the system is 10 J. What is change in internal energy ?

At $25\ ^\circ\text{C}$ standard enthalpy of combustion of $\text{H}_2$, Cyclohexene and cyclohexane are -241, -3800 and -3920 kJ $\text{mol}^{-1}$ respectively. What is the heat of hydrogenation of cyclohexene?