What will weigh more when a chemical change is complete? The reactants before the chemical reaction, or the product after the reaction is complete?

A. The reactant will
weigh more than
the product

B. They both will loose
mass after the
reaction

C. They both will weigh
the same

D. The product always
weighs more than
the reactant

Plzzz Hurry This is urgent

I guessed and got c and got it right

Explanation:

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.