a) `DeltaG` gives a criteria for spontaneity of reactions at a constant pressure and temperature. How is `DeltaG` helpful in precting the spontaneity of the reaction?
b) State and explain Hess's law of constant heat summation.

Explain the Hess's law of constant heat summation

Give the criteria for spontaneity of a process in terms of free energy change( DeltaG )

The difference of heat of reaction at constant pressure and at constant volume for combustion of 2 mol of liquid benzene at 300 K

The activation energy of a reaction is zero. Will the rate constant of the reaction depend upon temperature? Give reason.

Name the gas law which gives the relationship between the pressure and temperature of a fixed amount of gas at a constant volume.

Most of the naturally occurring processes are spontaneous. a) Give the criteria for spontaneity of a process in terms of free energy change ( DeltaG ) b) Exothermic reactions associated with a decrease in entropy are sponaneous at lower temperatures. Justify on the basis of Gibbs equation. c) Find the temperature above which the reactin MgO_((s))+C_((s))rightarrow Mg_((s))+CO_((g)) becomes spontaneous. (Given ( Delta_rH^theta=490kJmol^-1 & Delta_rS^theta=198JK mol^-1 )