Answer to Question #252390 in General Chemistry for Mallorie

Question

Calculate the standard enthalpy of formation of gaseous carbon dioxide (CO2) using the following information:

2 Ca(s) + O2(g) <- -> 2 CaO(s). TriangleH=-1270.2kJ

CaO(s) + CO2(g) <- -> CaCO3(s). TriangleH=-178.3kJ

2 C(s) + 2 Ca(s) + 3 O2(g) <- -> 2 CaCO3(s). TriangleH=-2413.8kJ

1)TriangleH = _____ kJ

(The answer is not -786.2, 786.2, or -787)

Answer 1

-1270.2+-178.3--2413.8

= 965.3kJ