What is the quantity of heat evolved when 111.9 grams of H2O(l) is formed from the combustion of H2(g) and O2(g)?

H2(g) + 1/2 O2(g) --> H2O(l) Delta Ho = -285.8 kJ

A. -0.4 kJ
B. 1776.7 kJ
C. 0.4 kJ
D. -1776.7 kJ
E. -6.2 kJ

1 answer

The equation tells us that 285.8 kJ of heat are released per mol of liquid water formed. I would see how many mols are in 111.9 grams of water and that times 285.8 kJ/mol will tell me how many kJ of heat are released.