Is n2o5 an empirical formula?

As a chemistry expert with a deep understanding of chemical formulas and their implications, I'm here to provide you with a comprehensive answer to your question regarding the empirical formula of a compound and how it relates to the molecular formula.

Empirical formulas are the simplest whole number ratios of atoms in a compound. They represent the composition of a substance in the most reduced form. On the other hand, the molecular formula of a compound indicates the exact number of each type of atom in a molecule of that substance. The molecular formula is a multiple of the empirical formula.

Let's take a closer look at the concept of empirical formulas and how they can be used to determine the molecular formula of a compound.

### Empirical Formula

The empirical formula N2O5 suggests that for every two nitrogen atoms, there are five oxygen atoms in the compound. This is the simplest ratio of nitrogen to oxygen in the compound.

### Molecular Formula

The molecular formula, which is a multiple of the empirical formula, indicates the actual number of atoms in a molecule of the compound. If the empirical formula is N2O5, the molecular formula could be N2O5 itself if it's already the simplest whole number ratio representing the molecule.

However, if we are given that the formula mass (which is the sum of the atomic masses of all atoms in the formula) is 108 amu (atomic mass units), we can calculate the molecular formula by considering the atomic masses of nitrogen (N) and oxygen (O). The atomic mass of nitrogen is approximately 14 amu, and that of oxygen is approximately 16 amu.

Given the empirical formula N2O5, the formula mass would be calculated as follows:
\[ (2 \times 14) + (5 \times 16) = 28 + 80 = 108 \, \text{amu} \]

This calculation shows that the empirical formula N2O5 already has a formula mass of 108 amu, which matches the given information. Therefore, the empirical formula is indeed the molecular formula in this case.

Now, let's address the second part of your question regarding compound A with an empirical formula of NO2. If this empirical formula is derived from a compound where the formula mass is also 108 amu, we can determine if this is the molecular formula or not.

The formula mass for the empirical formula NO2 would be:
\[ (1 \times 14) + (2 \times 16) = 14 + 32 = 46 \, \text{amu} \]

Since the formula mass of NO2 is 46 amu, which is less than the given 108 amu, NO2 cannot be the molecular formula. The molecular formula would be a multiple of the empirical formula that equals the given formula mass. To find the molecular formula, we would divide the given formula mass by the formula mass of the empirical formula:

\[ \frac{108 \, \text{amu}}{46 \, \text{amu}} = 2.34782609 \]

Since the result is not a whole number, we would round to the nearest whole number, which is 2. This means the molecular formula would be twice the empirical formula, which is N2O4.

In conclusion, the empirical formula N2O5 is also the molecular formula if its formula mass is 108 amu. For compound A with an empirical formula of NO2, the molecular formula, given the formula mass is 108 amu, would be N2O4.

Now, let's move on to the next step of your request.

A compounds empirical formula is N2O5. If the formula mass is 108 amu, what is the molecular formula? N2O4. A compounds empirical formula is NO2.