Question

During which of the following processes, does Entropy decrease ?

$ \left(a\right)$ Freezing of water to ice at $ {0}^{°} c$

$ \left(b\right)$ Freezing of water to ice at $ -{10}^{° } C$

$ \left(c\right)$

$ \left(d\right)$ Adsorption of $ CO\left(g\right)$ on lead surface.

$ \left(e\right)$ Dissolution of $ NaCl$ in water

• A. $\left(a\right),\left(b\right),\left(c\right)and\left(d\right)$ only
• B. $\left(a\right),\left(c\right)and\left(e\right)$ only
• C. $\left(a\right),\left(e\right)$ only
• D. $\left(b\right),\left(c\right)$ only

Answer 1

The correct option is A

$\left(a\right),\left(b\right),\left(c\right)and\left(d\right)$ only

Entropy:

Entropy is the measure of a system's thermal energy per unit temperature that is unavailable for doing work.

The explanation for the correct options.

For $\left(a\right),\left(b\right)$, the Freezing of water will decrease entropy as the particles will move faster.

For $\left(c\right)$, Entropy will decrease as the number of particles are decreasing.

For $\left(d\right)$, Absorption will lead to a decrease in entropy.

The explanation for the incorrect options.

For $\left(e\right)$, $NaCl\to N{a}^{+}+C{l}^{-}$, In this process, the Entropy will increase.

Therefore, the correct option is $\left(A\right)$