Question

The standard heats of combustion (δh∘) per mole of 1,3-butadiene, c4h6(g); butane, c4h10(g); and h2(g) are −2540.2,−2877.6, and −285.8kj, respectively. Use these data to calculate the heat of hydrogenation of 1,3-butadiene to butane. C4h6(g)+2h2(g)→c4h10(g)

Answer 1

solution:

Hydration is the addition of water; hydrogenation is the addition of hydrogen.  

desire rxn: _C4H6(g) + 2 H2(g)-----> C4H10(g)___dHhy = ??  

knowns:  

__________C4H6 + 11/2 O2 --------> 4CO2 + 3H2O______dHox = -2540.2 kJ/mole  

__________4CO2 + 5H2O -----------> C4H10 + 13/2 O2___-dHox = 2877.6 kJ/mole  

___________2(1/2 O2 + H2 -------------> H2O)___________2*dHox = 2(-285.8 kJ/mole)  

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