The answer is 4 (four).
Hope this helps!!! :)
The atomic mass of Aluminum is around 27 amu. There are two aluminum atoms, so it takes 54 amu. The gram-formula states that 1 mole of this compound has 342 grams. By definition, this means that the total amu of this compound is 342. Therefore, we divide 54 by 342 to get around 15.8 %.
Answer:
The answer to your question is -2855 J
Explanation:
Reaction
2C₂H₆ + 7O₂ ⇒ 4CO₂ + 6H₂O
Formula
Heat of reaction = ΔHrxn = ΣΔHrxn products - ΣΔHrxn reactants
Substitution
ΔHrxn = { 4(-393.5) + 6(-241.8)} - {2(-84.7) + 7(0)}
ΔHrxn = {-1574 -1450.8} - {-169.4}
ΔHrxn = -3024.8 + 169.4
ΔHrxn = -2855.4 J
