Consider the equation below.

[tex]\[ Na^{+} + Cl^{-} \rightarrow NaCl \][/tex]

Which statement best describes the relationship between the substances in the equation?

A. The number of sodium ions is equal to the number of formula units of salt.
B. The number of sodium ions is less than the number of chloride ions.
C. The number of chloride ions is less than the number of formula units of salt.
D. The number of sodium ions is two times the number of formula units of salt.



Answer :

Let's analyze the given chemical equation step by step:

[tex]\[ Na ^{+} + Cl ^{-} \rightarrow NaCl \][/tex]

1. Identifying the reactants and products:
- The reactants are the sodium ion ([tex]\(Na^{+}\)[/tex]) and the chloride ion ([tex]\(Cl^{-}\)[/tex]).
- The product is sodium chloride ([tex]\(NaCl\)[/tex]).

2. Understanding the formation of the product:
- Sodium ion ([tex]\(Na^{+}\)[/tex]) and chloride ion ([tex]\(Cl^{-}\)[/tex]) combine in a 1:1 ratio to form one formula unit of sodium chloride ([tex]\(NaCl\)[/tex]).

3. Balancing the equation:
- Since one sodium ion combines with one chloride ion to form one formula unit of sodium chloride, the equation is already balanced with a 1:1:1 ratio of [tex]\(Na^{+}\)[/tex], [tex]\(Cl^{-}\)[/tex], and [tex]\(NaCl\)[/tex].

4. Analyzing the relationship:
- The number of sodium ions ([tex]\(Na^{+}\)[/tex]) is equal to the number of chloride ions ([tex]\(Cl^{-}\)[/tex]).
- Each pair of sodium ion and chloride ion forms exactly one formula unit of sodium chloride ([tex]\(NaCl\)[/tex]).

Thus, the number of sodium ions is exactly equal to the number of formula units of salt (which is [tex]\(NaCl\)[/tex]) formed. This is the only statement that accurately captures the relationship described by the chemical equation.

Therefore, the best statement that describes the relationship between the substances in the equation is:

The number of sodium ions is equal to the number of formula units of salt.

The final answer is:

The number of sodium ions is equal to the number of formula units of salt.