Some fuel cells are powered by hydrogen. scientists are looking into the decomposition of water (h2o) to make hydrogen fuel with the of the sun’s energy. what challenge do scientists face with this task?
a.
decomposing water requires a high activation energy.
b.
the sun isn't a renewable resource.
c.
decomposing water results in toxic byproducts.
d.
scientists are uncertain what to do with the excess oxygen.

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.

2b2t

explanation:

2b2t

answeridentity;