Liquid acetaldehyde reacts according to the balanced equation. If a total of 5550 kJ of heat is generated in the reaction as written, how many grams of CH3CHO are consumed?

2 CH3CHO(l) + 5 O2(g) → 4 CO2(g) + 4 H2O(l) .

Enthalpy: -2335.0 kJ

Molar Mass
CH3CHO 44.05
O2 31.999
CO2 44.001
H2O 18.015

Question

Liquid acetaldehyde reacts according to the balanced equation. If a total of 5550 kJ of heat is generated in the reaction as written, how many grams of CH3CHO are consumed?

2 CH3CHO(l) + 5 O2(g) → 4 CO2(g) + 4 H2O(l) .

Enthalpy: -2335.0 kJ

Molar Mass
CH3CHO	 44.05
O2	 31.999
CO2	 44.001
H2O	 18.015

anonymous · Answer

Chemical equations express ratios based upon moles, so 2 moles of acetaldehyde generates 2335.0 kJ. 5550 kJ is more than twice as much energy, so you would have at least 5 moles of acetaldehyde (x moles/5550 kJ = 2 moles/2335.0 kJ)