Question

The enthalpy of vaporization of water is $386KJ$. What is change in entropy of water on boiling point.

• A. $0.5KJ$
• B. $1.02KJ$
• C. $1.5KJ$
• D. $22.05KJ$

Answer 1

Answer: (B)

$1.02KJ$

Solution:- (B) $1.03kJ$

Given that:-

$\Delta H=386kJ$

As the boiling point of water $100℃$,

$\therefore T=100℃=(100+273)=373K$

As the boiling point of water,

$\Delta G=0$

$\therefore \Delta S=\frac{\Delta H}{T}$

$\Rightarrow \Delta S=\frac{386}{373}$

$\Rightarrow \Delta S=1.02kJ$

Hence the change in entropy of water on boiling point $1.03kJ$.