Question

Please help! Explain how to get the correct answer.
When ammonia gas reacts with hydrogen gas, a white solid, ammonium chloride forms.
NH3(g) + HCl(g) -> NH4Cl(s)
If 6.02x10^23 molecules of ammonia react with 1.204x10^24 molecules of hydrogen chloride how many molecules are in the reaction vessel when the reaction is complete?
A. 1.00x10^23
B. 3.01x10^23
C. 6.02x10^23
D. 1.20x10^24
E. 1.80x10^24