Odisha Board Solutions for Chapter: Thermodynamics, Exercise 2: ADDITIONAL QUESTIONS

Define entropy and free energy of a system. Predict the feasibility of a reaction when both $∆\mathrm{H}$ and $∆\mathrm{S}$increase.

Predict the feasibility of a reaction when both $∆\mathrm{H}$ and $∆\mathrm{S}$decrease.

Predict the feasibility of a reaction when $∆\mathrm{H}$ decreases but $∆\mathrm{S}$increase.

Write note on enthalpy of formation.

Write note on enthalpy of combustion.

Write note on bond energy.

Write note on enthalpy of neutralisation.

State and explain Hess's law of constant heat summation. Discuss its application. Calculate the enthalpy of formation of methane. Given:

(a) $\mathrm{C} \left(\mathrm{graphite}\right) + {\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{CO}}_{2\left(\mathrm{g}\right)} ∆{\mathrm{H}}_{\mathrm{a}}=-393.5 \mathrm{kJ}$

(b) $2{\mathrm{H}}_{2\left(\mathrm{g}\right)}+{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) ∆{\mathrm{H}}_{\mathrm{b}}=-571.8 \mathrm{kJ}$

(c) ${\mathrm{CH}}_{4 \left(\mathrm{g}\right)} + 2{\mathrm{O}}_{2 \left(\mathrm{g}\right) }\to {\mathrm{CO}}_{2 \left(\mathrm{g}\right)}+2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{g}\right) }∆{\mathrm{H}}_{\mathrm{c}}=-890.3 \mathrm{kJ}$.