Final answer:
The number of nitrate ions present in both the reactants and products of the provided chemical equation is two, making option B the correct answer.
Step-by-step explanation:
The question asks about the number of nitrate ions present in the reactants and products of a chemical equation. Looking closely at the equation provided:
Ba(NO3)2 + 2LiOH → Ba(OH)2 + 2LiNO3
In the reactants, there is one formula unit of barium nitrate (Ba(NO3)2), which contains two nitrate ions. On the product side, there are two formula units of lithium nitrate (LiNO3), each containing one nitrate ion, for a total of two nitrate ions. Thus, there are two nitrate ions on both the reactant and product sides of the equation. The correct answer is therefore B: two in the reactants and two in the products. This analysis can be confirmed by the stoichiometry of the balanced chemical reactions provided where the number of nitrate ions remains constant, satisfying the Law of Conservation of Mass.