For a given reaction, if ΔH = 35.5 kJ/mol and ΔS = 83.6 J/K·mol, at what temperature is the reaction spontaneous?
(Assume ΔH and ΔS remain constant with temperature.)

For a given reaction, ∆H = 35.5 kJ mol^–1 and ∆S = 83.6 J K^–1 mol^–1. The reaction is spontaneous at:
[Note: Assume that ∆H and ∆S  do not vary with temperature]

1. T > 425K
2. All temperatures
3. T > 298K
4. T < 425K

The correct thermodynamic conditions for the spontaneous reaction at all temperatures is

$\left(\mathrm{a}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}>0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}<0$
$\left(\mathrm{b}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}>0$
$\left(\mathrm{c}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}<0$
$\left(\mathrm{d}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}=0$