\Delta G^\circ = \sum {G^\circ _f {\rm{products}}} - \sum {G^\circ _f {\rm{reactants}}}
% MathType!MTEF!2!1!+-
% feaafaart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB
% PrgifHhDYfgasaacH8YjY-vipgYlh9vqqj-hEeeu0xXdbba9frFj0-
% OqFfea0dXdd9vqai-hGuQ8kuc9pgc9q8qqaq-dir-f0-yqaiVgFr0x
% fr-xfr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeuiLdq
% Kaam4raiabgclaWkabg2da9maaqaeabaGaam4raiabgclaWoaaBaaa
% leaacaWGMbaabeaakiaabchacaqGYbGaae4BaiaabsgacaqG1bGaae
% 4yaiaabshacaqGZbaaleqabeqdcqGHris5aOGaeyOeI0Yaaabqaeaa
% caWGhbGaeyiSaa7aaSbaaSqaaiaadAgaaeqaaOGaaeOCaiaabwgaca
% qGHbGaae4yaiaabshacaqGHbGaaeOBaiaabshacaqGZbaaleqabeqd
% cqGHris5aaaa!5976!
Pasting the above "text" into MathType 5.0 will enter the above equation and make it possible to edit, save, and use in applications such as MS Word.