DeltaH and DeltaU are nearly the same in all the following processes except

Question

a.F2(g)+H2(g) --> 2HF(g)
b.3O2(g) --> 2O3(g)
c.CuO(s) +H2(g) --> Cu(s) +H20(g)
d.CH4(g) +CI2(g) --> CH3Cl(g) +HCl(g)
e.C6H6(s) --> C6H6(l)

Answer 1

Is delta U the change in energy?
Then delta H = delta U + P*delta V
Look for the processes in which the work (P*delta V) is zero (number of moles doesn't change or volume doesn't change). In that case, delta H = delta U.