Question

how much thermal energy would be produced by burning25.0 grams ethane? @Mathematics

Answer 1

In order to answer this question you have to look at the Bond enthalpy. Foe instance if
\[C _{2}H _{6}+O _ {2\rightarrow} 2CO _{2}+H _{2}O\] The equation is not balanced.
Sum up the bond enthalpy of ethan and oxygen in one side and sum up bond enthaply of water and carbon dioxide in the other side. Subtract the bond enthalpy of the left hand side from the right hand side and you will get your answer.