What do you understand by heat of combustion ?

What is entropy? What is its unit? Discuss the physical significance of entropy. Explain why the entropy of ice is less that of water.

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 $∆\mathrm{H}$ decreases but $∆\mathrm{S}$increase.

Write note on enthalpy of formation.

Write note on enthalpy of neutralisation.