Using standard heats of formation, calculate the standard enthalpy change for the following reaction. 2H2O2(l)2H2O(l) + O2(g)

Question

Using standard heats of formation, calculate the standard enthalpy change for the following reaction.

2H2O2(l)2H2O(l) + O2(g)

Answer 1

Use the following formula:

 

ΔHreaction= (ΣΔHproducts)-(ΣΔHreactants)

 

ΔHreaction= [(ΔHO2) + (ΔHH20)] - [(ΔHH2O2)]

 

You can easily find the values in a chemistry textbook or online.

 

ΔH O2= 0

ΔH H2O= −285.8 kj/mol

ΔH H2O2= −187.8 kj/mol 

 

Plug the values into the equation:

 

ΔH reaction= [(0) + (2 x -285.8)] - [(2 x -187.8)]= -196 kj/mol