Final answer:
Avogadro's number indicates the number of molecules in a mole but does not determine the molecular mass ratios of different gases. Nitrogen (N₂), oxygen (O₂), and chlorine (Cl₂) gases have different molecular masses, and therefore do not fit the ratios provided in the multiple-choice options.
Step-by-step explanation:
Avogadro's number relates the molecular masses of pure nitrogen gas (N₂), pure oxygen gas (O₂), and pure chlorine gas (Cl₂) through the concept of molar mass. Avogadro's number (6.022 × 10²³ particles per mole) implies that one mole of any substance, whether it's N₂, O₂, or Cl₂, contains the same number of molecules. However, their molecular masses are different due to the different atomic masses of nitrogen, oxygen, and chlorine. To find the molecular masses:
- N₂: has a molecular mass of approximately 28 u (2 × 14 u).
- O₂: has a molecular mass of approximately 32 u (2 × 16 u).
- Cl₂: has a molecular mass of approximately 71 u (2 × 35.5 u).
The molecular masses are not equal, nor do they share a common ratio. Hence, the answer to the student's question is that none of the options a), b), c), or d) correctly describe the relationship between the molecular masses of N₂, O₂, and Cl₂ when considering Avogadro's number.