How many moles of N_2O_4 are present in 76.3 g of N_2O_4, given that the molar mass of N_2O_4 is 92.02 g/mol?

• A. 0.829 mol
• B. 1.21 mol
• C. 0.675 mol
• D. 1.00 mol

Answer: (A)

Verified step by step guidance

1. Identify the given information: the mass of N_2O_4 is 76.3 g and the molar mass of N_2O_4 is 92.02 g/mol.
2. Recall the formula to calculate moles from mass and molar mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
3. Substitute the given values into the formula: \(\text{moles of } N_2O_4 = \frac{76.3\ \text{g}}{92.02\ \text{g/mol}}\).
4. Perform the division to find the number of moles (do not calculate the final value here, just set up the expression).
5. Interpret the result as the amount of substance in moles of N_2O_4 present in the given mass.