Consider the three reactions below

CHEMISTRY · Subjective · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

Consider the three reactions below, each carried out under standard conditions. I.

\mathrm{2\,SO_2(g)+O_2(g)\;\to\;2\,SO_3(g)}

II.

\mathrm{CaCO_3(s)\;\to\;CaO(s)+CO_2(g)}

III.

\mathrm{2\,H_2O_2(l)\;\to\;2\,H_2O(l)+O_2(g)}

Order the reactions from most negative to most positive

\Delta S^\circ

. Give a brief one-sentence justification for the reaction you place in the middle of your list.