Someone please help: 5.2cm^3 of gaseous hydrocarbon were exploded in excess oxygen. After cooling to the original room temperature and pressure a contraction in volume of 15.6cm^3 was observed. A further contraction of 10.4cm^3 was noted after treatment with concentrated KOH. What is the molecular formula for the hydrocarbon?

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

i think that the answer is c

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter