Question

Entropy is maximum in case of:
A. steam
B. water at \[0^\circ {\rm{C}}\]
C. water at \[4^\circ {\rm{C}}\]
D. ice

Answer 1

Hint:: 2^nd law of thermodynamics says that there is an entropy increase in the universe due to the change of entropy. The mathematical representation for the law is,
\[\Delta {S_{total}} = \Delta {S_{system}} + \Delta {S_{surrounding}} > 0\]

Complete step by step answer:

Let's understand what entropy is. The disorder in a system is termed entropy. The higher the disorder of a system, the more the measure of entropy is.
Among all the states of matter, such as liquids, solids, and gases, the gaseous state possesses the highest randomness or disorder.
Let's find the options one by one.
Option B is water at \[0^\circ {\rm{C}}\]. At \[0^\circ {\rm{C}}\], water is in the state of solid, that is, ice. Therefore, water at zero degrees Celsius possesses less value of entropy. So, option B is wrong.
Option C is water at \[4^\circ {\rm{C}}\]. At \[4^\circ {\rm{C}}\], water is the liquid state. Therefore, entropy is less. So, option C is wrong.
Option D is ice. We know that in solid-state entropy is less. So, option D is also incorrect.
Option A is steam. Steam is the gaseous form of water. As we know, entropy is maximum in a gaseous state. Therefore, the entropy of steam is maximum among the given options.

Hence, option A is right.

Note: The 1^st law of thermodynamics says the difference between the addition of heat to the system and work completed by the system gives the system's internal energy change. The mathematical representation is, \[\Delta U = Q - W\] .Here, Q is heat and W is work and \[\Delta U\]is internal energy change.