## Enthalpy vs. Entropy

Connie2I
Posts: 29
Joined: Fri Sep 29, 2017 7:07 am

### Enthalpy vs. Entropy

What is the conceptual difference between calculating the standard enthalpy of a phase change vs. the standard entropy of a phase change?

Vivian Nguyen
Posts: 66
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 2 times

### Re: Enthalpy vs. Entropy

Hello, the standard enthalpy of a phase change is the change in enthalpy required to supply the energy needed to carry out that certain phase change in a specific substance.
Meanwhile, the entropy of a phase change deals with the change in the number of states (disorder) of the substance.

Angel Gomez 1K
Posts: 36
Joined: Fri Sep 29, 2017 7:04 am

### Re: Enthalpy vs. Entropy

Would you mind explaining why enthalpy can be measured as an amount altogether but entropy can only be measured by the changes in it?

Marina Georgies 1C
Posts: 30
Joined: Sat Jul 22, 2017 3:00 am

### Re: Enthalpy vs. Entropy

Enthalpy can be measured quantitatively because of processes like calorimetry. It is essentially heat, and we use temperature to measure it directly. Entropy is the measure of how disordered a system is, so it is harder to give it a number value, however; the equation S=kblnW allows you to calculate a value for entropy. hope this helps

Warda Sahib 2J
Posts: 29
Joined: Thu Jul 13, 2017 3:00 am

### Re: Enthalpy vs. Entropy

Entropy is a measure of disorder or randomness of a system. Enthalpy is defined as the sum of internal energy of a system and the product of the pressure and volume of the system.