The chemical reactions for the given substances would be as follows:

H2SO4 (sulfuric acid) + H2 (hydrogen gas) = H2SO4 + H2O

H2 (hydrogen gas) + HCl (hydrochloric acid) = 2HCl

CuCl2 (copper(II) chloride) + Cu(OH)2 (copper(II) hydroxide) = 2CuCl + 2H2O