What is the answer for this question

The answer to your question is the second choice

Explanation:

Formula to calculate the heat of any substance

             Q cal= mCcal ΔTcal

Formula to calculate the heat of a metal. The heat will be negative because it releases heat.

                  Qm = -mCmΔTm

Now equal both formula

                   Qcal = Q m

           mCcalΔTm = -mCmetΔTmet

-Solve for Cmet

                 Cmet = -[mCcalΔTm] / mΔTmet

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.

the answer is 75.0%.