Answer: c. The reactant that is used up before the others
Explanation:
For example:
If we are given 100 g of
and 100 g of calcium.
As can be seen from the chemical equation, 2 moles of hydrochloric acid react with 1 mole of calcium.
According to mole concept, 1 mole of every substance weighs equal to its molar mass.
Thus
of of hydrochloric acid reacts with 40 g of calcium.
100 g of hydrochloric acid react with=
of calcium
Thus HCl is the limiting reagent as it limits the formation of product and calcium is the excess reagent as (100-54.79)=45.21 g is left unreacted.
Thus HCl which is a limiting reagent will be used up before Calcium.