If bond formation energy of $\mathrm{H}-\mathrm{H}$ bond is $-433 \mathrm{~kJ} \mathrm{~mol}^{-1}$ find the bond dissociation energy for 0.5 mole $H_{2(g)}$.

What is the value of standard enthalpy of formation of dihydrogen?

Calculate Gibbs energy change for a reaction having $\Delta \mathrm{H}=31400 \mathrm{~J}, \Delta \mathrm{~S}=32 \mathrm{~J} \mathrm{~K}^{-1}$ at $1000^{\circ} \mathrm{C}$ ?

If 100 L gas is enclosed in a cylinder, absorbs 302.6 J of heat and expands to 200 L against constant external pressure of 2 atm . Calculate internal energy change of the gas.