Problem: Acetone, CH3COCH3, is a liquid solvent. The enthalpy change at 25 ˚C and 1 atm for the complete burning of 1 mol of acetone in oxygen to give CO2(g) and H2O(l) is -1791 kJ. Calculate the standard enthalpy of formation of acetone.

FREE Expert Solution
90% (8 ratings)
FREE Expert Solution

We’re being asked to determine the standard enthalpy change of formation (ΔH˚f) for acetone. Recall that ΔH˚rxn can be calculated from the enthalpy of formation (ΔH˚f) of the reactants and products involved



We’re given the ΔH˚rxn for the combustion of 1 mole of acetone. The chemical equation for that reaction is:

CH3COCH3(l) + O2(g) → CO2(g) + H2O(l)


This equation is not yet balanced. To balance it, we have to make sure that the number of elements on both sides is equal.


Balance C: We have 3 C on the reactant side and 1 C on the product side – add a coefficient of 3 to CO2:

CH3COCH3(l) + O2(g) → 3 CO2(g) + H2O(l)


Balance H: We have 6 H on the reactant side and 2 H on the product side – add a coefficient of 3 to H2O:

CH3COCH3(l) + O2(g) → 3 CO2(g) + 3 H2O(l)


Balance O: We have 1 + 2 = 3 O on the reactant side and 3(2) + 3(1) = 9 O on the product side – add a coefficient of 4 to O2:

CH3COCH3(l) + 4 O2(g) → 3 CO2(g) + 3 H2O(l)


90% (8 ratings)
View Complete Written Solution
Problem Details

Acetone, CH3COCH3, is a liquid solvent. The enthalpy change at 25 ˚C and 1 atm for the complete burning of 1 mol of acetone in oxygen to give CO2(g) and H2O(l) is -1791 kJ. Calculate the standard enthalpy of formation of acetone.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Enthalpy of Formation concept. You can view video lessons to learn Enthalpy of Formation. Or if you need more Enthalpy of Formation practice, you can also practice Enthalpy of Formation practice problems.

What is the difficulty of this problem?

Our tutors rated the difficulty ofAcetone, CH3COCH3, is a liquid solvent. The enthalpy change ...as high difficulty.

How long does this problem take to solve?

Our expert Chemistry tutor, Dasha took 6 minutes and 48 seconds to solve this problem. You can follow their steps in the video explanation above.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Carlson's class at UWM.