Question #6837f

1 Answer
Mar 29, 2016

The limiting reagent is the one that was only 0.237 moles. The other one is the excess reagent.

Explanation:

The carbonate is provided by the Na2CO3 and the magnesium from the Mg(NO3)2.6H2O. ONLY the Mg and CO3 in the final product matter. First, a balanced equation is always required.

Mg(NO3)2.6H2O + Na2CO3MgCO3(s)+2NO13+2Na1+ (water is in solution)

Then calculate the number of moles in 2.00g MgCO3. 2.00/84.3 = 0.0237. This is then also the total number moles of Mg and CO3 used. Whichever reactant was present in larger quantity (no quantities were specified in the question) is the excess reagent. The other one is the limiting reagent.