Question

Does the following reaction show an increase or decrease in entropy?
${{H}_{2}}O(l)\to {{H}_{2}}O(s)$

Answer 1

The rate or degree of dis-orderness in a system is going to measure with entropy. If there is high dis-orderness in a system then entropy of the system is high and the dis-orderness in the system is less than the entropy will be less.

Complete answer:
- In the question it is given the chemical reaction mentioned in the question does show the increase or decrease in entropy.
- The chemical reaction is as follows.
${{H}_{2}}O(l)\to {{H}_{2}}O(s)$
- From the above chemical reaction we can say that water in liquid state is going to convert to water in solid state.
- We know that the water in liquid state moves very freely and occupies the maximum space available. Means water in liquid state has high entropy.
- Coming to water in solid state (Ice cubes) occupies a fixed position and there is no space available to move randomly in a solid state. Then water in solid state has less entropy value in solid state.
- Therefore in the given chemical reaction the entropy of the system (liquid to solid) is going to decrease from liquid state to solid state.

Note:
If we are going to talk about entropy, the entropy of a system in a gaseous state has high entropy when compared to the same system in liquid state. The entropy of a system in liquid state is high when compared to the system which is in solid state.