Question

Which of the following option(s) will show a decrease in Gibbs energy?

• A. Combustition of propane at 1 bar and 500K.
• B. Vaprourisation of any liquid at 1 atm and above its normal boiling point.
• C. Fusion of $H_{2}O$ at 1 atm and $0^C$ if its normal melting point is $0^{o}C$.
• D. Vaprourisation of $H_{2}O$ at ${100}^{o}C$ and 1 bar if its normal boiling point is ${100}^{o}C$.

Answer 1

Answer: (A)

Combustition of propane at 1 bar and 500K.

$C_3{H}_8+5O_2⟶3C{O}_2+4H_{2}O\left(e\right)$

{$6$} {$3$} $\left[A\right]$

$△G^{\circ }=△G^{\circ }products-△G^{\circ }reactants$

$△n=3-6=-3$

Thus option A is the answer