To calculate the number of molecules in 6.00 moles of hydrogen sulfide, H2S, the equivalence factor used is Avogadro's number equal to (6.022 x 10^23 molecules/mole). The answer is 6.00 moles of hydrogen sulfide * (6.022 x 10^23 molecules/mole) equal to 3.61 x10^24 molecules.