State variables of a system are physical quantities whose change in value only depends on initial and final state of system and doesn't follow on the path which system follows during change.

Internal Energy of a system is a sum of all kinds of energies possessed within it.

$\Delta H_{vap}ofwater=2.072318=37.30KJmo{l}^1$

$\Delta S_{vap}=\frac{\Delta H_{vap}}{T_b}=\frac{37.30KJmo{l}^1}{373K}=0.1kJmo{l}^1{K}^1$

$\Delta G_{vap}=\Delta H\left(kJmo{l}^1\right)T\left(K\right)\Delta S\left(kJmo{l}^1\right)$

$=37.303730.1=0$

The amount of heat evolved or absorbed in a chemical reaction when the number of moles of the reactants as represented by the chemical equation have completely reacted, is called the enthalpy of reaction.

Hess's law states that the change in enthalpy for a reaction is the same whether the reaction takes place in one or a series of steps.

Path I :
CH4(g)+2Cl2(g)CH2Cl2(g)+2HCl(g)ΔH10=202.3kJ

Path II :
CH4(g)+Cl2(g)CH3Cl(g)+HCl(g)ΔH20=98.3kJ
CH3Cl(g)+Cl2(g)CH2Cl2(g)+HCl(g)ΔH30=104.0kJ

Adding two steps
C...

The differences between Intensive and Extensive properties are mentioned below.

Intensive property	Extensive property
It is independent of amount of system and depends on nature od system.	It is dependent on the amount of system.
Eg: Refractive index, Sp heat capacity	Eg: Mass, enthalpy

State function of a system is the thermodynamic function that depends on the state but not on the path along which the system is carried out. example: Pressure, Temperature, Volume.

Enthalpy of combustion	Enthalpy of Formation
It may be defined as the amount of heat released when one mole of the substance is completely burnt in the presence of oxygen.	It is defined as the change in the enthalpy during the formation of one mole of the substance from its constituents elements involved in the reaction.
It tells us about the amount of heat that is added or released during the chemical reaction.	It tells us about the change involved in the enthalpy during the...