Nitrogen 1N22 and hydrogen 1H22 react to form ammonia 1NH32. Consider the mixture of N2 and H2 shown in the accompanying diagram. The blue spheres represent N, and the white ones represent H. (d) If so, how many of which type are left over?
How many N2 molecules are left over?

Verified step by step guidance

1. Identify the balanced chemical equation for the reaction: \( N_2 + 3H_2 \rightarrow 2NH_3 \).
2. Determine the initial number of \( N_2 \) and \( H_2 \) molecules from the diagram.
3. Calculate the limiting reactant by comparing the mole ratio of \( N_2 \) to \( H_2 \) with the stoichiometric ratio from the balanced equation.
4. Use the limiting reactant to determine how many \( N_2 \) molecules are consumed in the reaction.
5. Subtract the number of \( N_2 \) molecules consumed from the initial number to find how many \( N_2 \) molecules are left over.

Key Concepts

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows us to calculate how much of each substance is consumed or produced based on balanced chemical equations. In this case, understanding the stoichiometric ratios of nitrogen and hydrogen in the formation of ammonia is essential to determine how many molecules remain after the reaction.

Molecular Representation

Molecular representation involves visualizing molecules using symbols or models to understand their composition and structure. In the given question, nitrogen (N2) is represented by blue spheres and hydrogen (H2) by white spheres. This representation helps in identifying how many molecules of each reactant are present and how they interact during the reaction to form ammonia (NH3).

Limiting Reactant

The limiting reactant is the substance that is completely consumed first in a chemical reaction, thus determining the maximum amount of product that can be formed. Identifying the limiting reactant is crucial for calculating how many molecules of the other reactants remain after the reaction. In this scenario, knowing which reactant (N2 or H2) limits the formation of ammonia will help answer how many N2 molecules are left over.