# Entropy vs Enthalpy – Difference [Explained with Pdf]

One of the differentiating point for Entropy vs Enthalpy is that the entropy is a measure of the randomness of molecules while the enthalpy is the total energy associated with the system.

Before knowing the entropy and enthalpy difference, let’s know briefly about them.

## What is Enthalpy?

Enthalpy for the thermodynamic system is the sum of the internal energy and the product of pressure and volume.

Enthalpy is denoted by the symbol ‘H’ and Mathematically it is given by,

H = U + Pv

The enthalpy gives the total energy of the system. The unit of the enthalpy in the SI system is Joule (J) and in the FPS system is Btu.

## What is Entropy?

Entropy is known as the measure of the disorder or randomness of molecules in the system.

The entropy is the extensive property and is denoted by the symbol ‘S’. The change in entropy of the system is given by the ratio of heat transfer to the absolute temperature.

Mathematically, change in entropy is given by,

\Delta S = \frac{\Delta Q}{T}

The unit of the change in entropy in the SI system is Joules/Kelvin (J/K) and in the FPS system is BTU/°F

## Difference between enthalpy and entropy:

FAQ’s:

1. What is difference between entropy and enthalpy?

The enthalpy and entropy can be compared as the enthalpy is the total energy of the system while the entropy is the measure of randomness or disorder of the molecules in the system.

2. What is the relation between enthalpy and entropy?

The change in the entropy is the change in enthalpy per average absolute temperature.