Determine the molecular formula of a compound that has a molar mass of 92.0 g/mol and an empirical formula of NO₂.

• A. NO₂
• B. N₂O₄
• C. NO
• D. N₂O

Answer: (B)

Verified step by step guidance

1. First, calculate the molar mass of the empirical formula NO₂. The atomic mass of nitrogen (N) is approximately 14.01 g/mol, and the atomic mass of oxygen (O) is approximately 16.00 g/mol. Therefore, the molar mass of NO₂ is calculated as: $14.01+2\times 16.00$ g/mol.
2. Next, determine the ratio of the molar mass of the compound to the molar mass of the empirical formula. This is done by dividing the given molar mass of the compound (92.0 g/mol) by the molar mass of the empirical formula calculated in the previous step.
3. The result from the division in the previous step will give you a whole number or a number very close to a whole number. This number represents how many times the empirical formula must be multiplied to obtain the molecular formula.
4. Multiply the subscripts in the empirical formula NO₂ by the whole number obtained in the previous step to find the molecular formula. This involves multiplying each subscript in NO₂ by the whole number.
5. Finally, write the molecular formula using the new subscripts obtained from the multiplication. This will give you the molecular formula of the compound.