Question

8Mg + S8 → 8MgS

If 80 moles of Mg and 15 moles of S8 are allowed to react, _?_moles of MgS will be formed. Mg is the _?_ (limiting or excess) reactant and S8 is the _?_(limiting or excess) reactant. _?_moles of the excess reactant will remain unreacted.

Answer 1

8Mg + S₈ → 8MgS

According to the above balanced equiation ,

8 moles of Mg reacts with 1 mole of S₈       

8x10=80 moles of Mg reacts with 1x10 = 10 mole of S₈       

So 15 - 10 = 5 moles of S₈ left unreacted in the solution.So S₈ is the excess reactant.

Since all the mass of Mg completly reacted, Mg is the limiting reactant.

From the balanced equation ,

8 moles of Mg produces 8 moles of MgS

So 80 moles of Mg produces 80 moles of MgS

Therefore the number of moles of MgS produced are 80 moles