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Chemistry Homework Help => General Chemistry => Topic started by: JCbrotherhood on November 06, 2012, 08:07:17 PM

Title: Hess's law
Post by: JCbrotherhood on November 06, 2012, 08:07:17 PM
Use Hess' law to determine the H for the following reaction
4 CO(g) + 8H2(g) --> 3CH4(g) + CO2(g) + 2H2O(l)

Given the following information

C(graphite) + 1/2O2(g) -> CO(g)  H = -110:5 kJ
CO(g) + 1/2O2(g) --> CO2(g)  H = -283:5 kJ
H2(g) + 1/2O2(g) --> H2O(l)  H = -285:8 kJ
C(graphite) + 2H2(g) --> CH4(g) H = -74:81 kJ
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(l) H = -890:3 kJ

I got -749.5 kj but I think i messed up the mole ratio multiplication at the end.