Thermodynamics Test - 2

For the expansion of a gas under adiabatic conditions, the internal energy of the gas is utilized for the expansion work and as a result the internal energy decreases and so does the temperature of the gas.

Heat change measured in a closed vessel is ΔE.

Thermal capacity is the amount of heat required to raise the temperature of a body by 1 K.

Specific heat = Thermal capacity × mass of the object

Water equivalent is the amount of water that would absorb the same amount of heat as the thermal capacity of the material.

More is the number of C–H bonds, higher is the rate of combustion.

Hess's law deals with heat changes during processes.

It states that:

The heat of any reaction ΔH∘f for a specific reaction is equal to the sum of the heats of reaction for any set of reactions which in sum are equivalent to the overall reaction:

Nernst 3^rd law postulated that a pure crystalline substance at absolute zero temperature has zero entropy.

Only coupled reactions are possible with ΔG⁰ as positive.

J/k/mol are units of entropy.

Internal energy and enthalpy of a system cannot be determined in absolute terms.

Although it is not practically possible to calculate the absolute entropy of a system but there is a way to theoretically approximatly calculate an absolute value for entropy
using to the third law of thermodynamics.

dS=δq/T.

By the definition, a perfect crystal at 0 K would have an entropy S=0.