Question

1-Butene (CH2=CHCH2CH3) burns in the presence of O2 to produce CO2 and H2O. Write the balanced chemical equation for this reaction (omit physical states and use condensed molecular formulas).

CH2CHCH2CH3+6O2=4CO2+4H2O

Answer 1

This is ok but you omitted the double bond in CH2=CHCH2CH3. The double bond needs to be there (even though it's a condensed formula). When it's omitted the observer doesn't know if it is a double bond or if you just forget and left out the two H atoms.