For which of the following processes is `DeltaS` negative?

Options

A. `H_(2)(g) rarr 2H(g)`
B. `N_(2)(g) " 1 atm" rarr N_(2)(g) 8` atm
C. `2SO_(3)(g) rarr 2SO_(2)(g) + O_(2)(g)`
D. `C_(("diamond")) rarr C_(("graphite"))`

Answer

B

Explanation

(a) `H_(2)(g) rarr 2H(g) Delta n_(g) gt 0 rArr Delta S gt 0`
(b) `N_(2)(g) " 1 atm " rarr N_(2)(g)` 8 atm
As pressure increases, the motion of gas molecules decreases and thus disorder decreases. `Delta S lt 0`
(c) `2SO_(3)(g) rarr 2SO_(2)(g) + O_(2)(g) Delta n_(g) gt 0 rArr Delta S gt 0`
(d) `C_(("diamond")) rarr C_(("graphite"))` This is an exothermic reaction thus `Delta S` is positive.