What is the molecular formula of a compound that has a molar mass of 92g/mol and an empirical formula of NO2?
Understand the Problem
The question asks to determine the molecular formula of a compound given its molar mass and empirical formula. You need to calculate the ratio between the molar mass and the empirical formula mass to find the multiplier for the empirical formula to obtain the molecular formula.
Answer
$N_2O_4$
Answer for screen readers
The molecular formula is $N_2O_4$.
Steps to Solve
- Calculate the molar mass of the empirical formula $NO_2$
The molar mass of Nitrogen (N) is approximately 14 g/mol, and the molar mass of Oxygen (O) is approximately 16 g/mol. So we calculate the mass of $NO_2$
$14 + 2(16) = 14 + 32 = 46 \text{ g/mol}$
- Determine the ratio between the molar mass and the empirical formula mass
To find the multiplier to apply to the empirical formula, divide the molar mass of the compound by the molar mass of the empirical formula.
$\text{Ratio} = \frac{\text{Molar mass}}{\text{Empirical formula mass}} = \frac{92 \text{ g/mol}}{46 \text{ g/mol}} = 2$
- Determine the molecular formula
Multiply the subscripts in the empirical formula ($NO_2$) by the ratio calculated in the previous step, which is 2.
$N_{1\times2}O_{2\times2} = N_2O_4$
The molecular formula is $N_2O_4$.
More Information
Dinitrogen tetroxide ($N_2O_4$) is a colorless liquid or gas at room temperature and is a powerful oxidizing agent.
Tips
A common mistake is incorrectly calculating the molar mass of the empirical formula, or dividing the empirical formula mass by the molar mass instead of the other way around. Always double-check your calculations and make sure that you are dividing the molar mass by the empirical formula mass.
AI-generated content may contain errors. Please verify critical information
