To determine the correct way to describe the [tex]\( H_2 \)[/tex] component in the given chemical reaction:
[tex]\[ 2 NH_3(g) \rightarrow N_2(g) + 3 H_2(g) \][/tex]
we need to review each of the provided options carefully:
1. 3 formula units [tex]\( H_2 \)[/tex]:
- In chemistry, a formula unit refers to the smallest amount of a substance that has the composition given by the chemical formula. Here, [tex]\( H_2 \)[/tex] indicates molecular hydrogen, which means one molecule of [tex]\( H_2 \)[/tex].
- Since the reaction produces three [tex]\( H_2 \)[/tex] molecules, describing it as "3 formula units [tex]\( H_2 \)[/tex]" is both accurate and correct.
2. 3 L[tex]\( H_2 \)[/tex]:
- "L" stands for liters, which is a measure of volume. The question asks for a description in terms of chemical units.
- Therefore, describing the [tex]\( H_2 \)[/tex] as "3 L [tex]\( H_2 \)[/tex]" is incorrect in the context of this reaction because it misinterprets the chemical production in terms of volume rather than quantity of molecules.
3. 2 molecules [tex]\( H_2 \)[/tex]:
- The balanced chemical equation clearly shows that three molecules of [tex]\( H_2 \)[/tex] are produced, not two.
- So, "2 molecules [tex]\( H_2 \)[/tex]" is incorrect.
4. 4 atoms [tex]\( H_2 \)[/tex]:
- Each [tex]\( H_2 \)[/tex] molecule consists of 2 hydrogen atoms. Therefore, three [tex]\( H_2 \)[/tex] molecules would consist of 6 hydrogen atoms.
- Describing it as "4 atoms [tex]\( H_2 \)[/tex]" is incorrect since it does not match the quantity produced in the reaction.
Therefore, the correct and accurate description of the [tex]\( H_2 \)[/tex] component in the reaction is:
3 formula units [tex]\( H_2 \)[/tex].
