Which statement is true about limiting reactants?
a). the limiting reactant in a reaction is the first reactant to be completely converted to moles.
b). the limiting reactant in a reaction is the first reactant to be completely converted to products.
c).the limiting reactant in a reaction is the first reactant to be completely converted to energy.
d).the limiting reactant in a reaction is the first reactant to be completely converted to heat.

Ans: B). The limiting reactant in a reaction is the first reactant to be completely converted to products.

In a chemical reaction, the limiting reagent is one with a lower number of moles. Thus, the limiting reactant will be consumed first and will dictate the amount of product that can be formed.

For example consider the reaction between 1 g of Mg and 2 g of O to form MgO

# moles of Mg =

# moles of Oxygen =

since moles of Mg is less than that of oxygen, Mg will be the limiting reactant. Thus, it will be consumed first and will be completely converted into MgO.