Enthalpy of atomisation of ${\mathrm{NH}}_3$ and ${\mathrm{N}}_2{\mathrm{H}}_4$ are $\mathrm{x} \mathrm{KCal} {\mathrm{mol}}^{-1}$ and $\mathrm{y} \mathrm{KCal} {\mathrm{mol}}^{-1}$ respectively. Calculate average bond energy of $\mathrm{N}-\mathrm{N}$ bond:

Given the following standard enthalpies of reaction: [Thermodynamics & Thermochemistry]
(i) Enthalpy of formation of water $=-68.3 \mathrm{kCal}/\mathrm{mol}$
(ii) Enthalpy of combustion of acetylene $=-310.6 \mathrm{kCal}/\mathrm{mol}$
(iii) Enthalpy of combustion of ethylene $=-337.2 \mathrm{kCal}/\mathrm{mol}$

Calculate the heat of reaction for the hydrogenation of acetylene into ethylene (in $\mathrm{kCal}/\mathrm{mol}$) at constant pressure. Report your answer in terms of magnitude, rounding it off to the nearest whole number.

Predict the total number of intensive properties:

($\mathrm{i}$) Free energy

($\mathrm{ii}$) Critical density

($\mathrm{iii}$) Viscosity

($\mathrm{iv}$) Specific heat capacity

($\mathrm{v}$) molar heat capacity

($\mathrm{vi}$) Kinetic energy

($\mathrm{vii}$) Specific gravity

($\mathrm{viii}$) Dielectric constant

($\mathrm{ix}$) $\mathrm{pH}$

The internal energy of a substance :