Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.

Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
Grade: Upto college level




10 years ago

Answers : (1)

AKASH GOYAL AskiitiansExpert-IITD
419 Points

Dear Student

The extent of disorder or randomness in a system may be expressed by a property known as entropy. Entropy may be termed as the property of a system which measures the degree of disorder or randomness in the system. It is generally expressed by the symbol, S. Entropy like internal energy and enthalpy, is a state function and change in entropy therefore, depends only on the initial and final states of the system. The change in entropy during the process when a system undergoes a change from one state to another is represented by DS. Thus, DS = S(final state) - S(initial state) and for chemical reactions, DS = S(products) - S(reactants). For a reversible process at equilibrium, the change in entropy may be expressed as:

DS = qrev / T

where qrev represents the heat supplied at temperature T in a reversible process.

Units of entropy

Since entropy change is expressed as heat divided by temperature, the units of entropy are calories per degree (expressed as entropy units eu) or joules per kelvin, JK-1 (expressed as EU).

Physical meaning of Entropy

The physical meaning of entropy is that entropy is a measure of degree of disorder (or randomness) of a system. The relation between entropy and disorder provides a suitable explanation for entropy change in various processes. The greater the disorder in a system, the higher is the entropy. Obviously, for a given substance the solid state is the state of lowest entropy (most ordered state), the gaseous state is the state of highest entropy and the liquid state, is intermediate between the two. In the case of mixing of two gases when the stopcock is opened, the gases mix to achieve more randomness or disorder. In this case, there is no exchange of matter or energy between the system and the surroundings. The change occurs from ordered state (less entropy) to disordered state (higher entropy). Thus the change in entropy is positive.


All the best.                                                           


AskiitiansExpert-IIT Delhi


Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively :Click here to download the toolbar..

10 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Course Features

  • 101 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution

Course Features

  • 110 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions

Ask Experts

Have any Question? Ask Experts
Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details