16.0 g sample of iron was heated from 2.00°C to 43.0 °C. It absorbed 193.0 J of energy as heat. What is the specific heat of this piece of iron?
0.294 J/gºC
w
849 J/gºC
0.268 J/g °C
0 -0.294 J/g°C

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.

10 years is the answer

the answer is option a.