Lenthionine, a naturally occurring sulfur compound, gives shiitake mushrooms their interesting flavor. The compound is composed of carbon, sulfur, and hydrogen. A 5.000 gram sample of lenthionine contains 0.6357 g carbon and 0.1070 g hydrogen, and the remainder is sulfur. The molar mass of lenthionine is 188.4 g/mol. Determine the chemical formula for lenthionine.

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.