Without doing any calculations, determine the sign of ΔSsys and ΔSsurr for each of the chemical reaction. Predict under what temperatures (all, low, or high), if any, the reaction will be spontaneous? C3H8(g)+5O2(g)→3CO2(g)+4H2O(g) ΔH_"rxn"^o =−2044kJ

Nov 3, 2015

$\Delta {S}_{s y s} > 0$
$\Delta {S}_{s u r r} > 0$
$\Delta {S}_{u n i} > 0$
All temperature will be spontaneous.

Explanation:

$\Delta {S}_{s y s} > 0$ as there are more gaseous products than reactants.

$\Delta {S}_{s u r r} > 0$ as heat is released to the surroundings.

$\Delta {S}_{u n i} > 0$ as both $\Delta {S}_{s y s}$ and $\Delta {S}_{s u r r} > 0$ are negative.

At all temperature, the above hold true. $\Delta {S}_{u n i} > 0$ implies that the reaction will be spontaneous at all temperatures.