Given that the molar mass of NO2 is 46.01 g/mole, how many moles are present in 114.95 g?

To determine the number of moles present in a certain mass of a substance, the molar mass is used as a conversion factor. For nitrogen dioxide (NO2), with a molar mass of 46.01 g/mole, the number of moles can be calculated using the formula:

Number of moles = Mass of substance (g) / Molar mass (g/mole).

In this case, the mass is 114.95 g. By substituting the values into the formula:

Number of moles = 114.95 g / 46.01 g/mole ≈ 2.498 mol.

This calculation indicates that approximately 2.498 moles of NO2 are present in 114.95 g of the substance, confirming that the correct choice reflects the precise application of the formula based on the molar mass provided. Understanding this conversion is fundamental in analytical chemistry, as it links mass measurements to the amount of substance in terms of moles, which is essential for stoichiometric calculations and reactions.