Question

At 298 K the entropy of rhombic sulphur 32.04 J/mol K and that of monoclinic sulphur is 32.68 J/mol K. The heat of their combustion are respectively $-298246$ and $-297948J$ $mo{l}^{-1}.$ $\Delta G$ for the reaction; $S_{rhormbic}\to S_{monoclinic}$ will be :

• A. 107.28 J
• B. 10.728 J
• C. 107.28 kJ
• D. 10728 J

Answer 1

Answer: (A)

107.28 J

$S_{rhombic}\to S_{momnoclinic}$

$\Delta H=-297948-(-298246)=298J$

$\Delta S=-32.68-32.04=0.64J/(mol.K)$

$\Delta G=\Delta H-T\Delta S=298-298\times 0.64=107.28J$