Answer to Question #114564 in Chemistry for Nikki

Question

Using CO2 = -393.5 kj/mol and H2O = -285.8 kj/mol determine delta H for C4H10

Answer 1

The combustion of butane (C₄H₁₀)can be determined as following:

C₄H₁₀ + 6.5O₂ --> 4CO₂ + 5H₂O

According to the equation:

ΔH_reaction = ΔH_products - ΔH_reactants

From here:

ΔH_reactants = ΔH_products - ΔH_reaction

As ΔH_reaction = -2877.5 kJ/mol (table value) and ΔH_oxygen = 0:

ΔH_butane = ΔH_products - ΔH_reaction= (4ΔH_{carbon dioxide} + 5ΔH_water) - ΔH_reaction = 4 × (-393.5 kJ/mol) + 5 × (-285.8 kJ/mol) - (-2877.5 kJ/mol) = -125.5 kJ/mol

Answer: -125.5 kJ/mol