Calculate the empirical formula for each of the following natural flavors based on their elemental mass percent composition.
nitroglycerin (used medically as a vasodilator to treat heart conditions): C 15.87% H 2.22% N 18.50% O 63.41%.
Express your answer as a chemical formula.
ll;;l
To calculate the empirical formula of nitroglycerin, we need to find the simplest whole-number ratio of the atoms present in the compound.
First, we need to convert the mass percent composition to grams. For a convenient calculation, let's assume we have 100g of the compound. This means we have:
- Carbon (C): 15.87g
- Hydrogen (H): 2.22g
- Nitrogen (N): 18.50g
- Oxygen (O): 63.41g
Next, we need to find the moles of each element. To do this, we divide the mass of each element by its molar mass. The molar masses of the elements are:
- Carbon (C): 12.01 g/mol
- Hydrogen (H): 1.01 g/mol
- Nitrogen (N): 14.01 g/mol
- Oxygen (O): 16.00 g/mol
Using these values, we can calculate the moles of each element:
- Moles of Carbon (C) = 15.87g / 12.01 g/mol = 1.32 mol
- Moles of Hydrogen (H) = 2.22g / 1.01 g/mol = 2.20 mol
- Moles of Nitrogen (N) = 18.50g / 14.01 g/mol = 1.32 mol
- Moles of Oxygen (O) = 63.41g / 16.00 g/mol = 3.96 mol
Now, we need to determine the simplest whole-number ratio by dividing the moles of each element by the smallest number of moles (in this case, 1.32 mol):
- Carbon (C): 1.32 mol / 1.32 mol = 1
- Hydrogen (H): 2.20 mol / 1.32 mol ≈ 1.67
- Nitrogen (N): 1.32 mol / 1.32 mol = 1
- Oxygen (O): 3.96 mol / 1.32 mol ≈ 3
Since we need whole-number ratios, we can multiply all the values by 3 to achieve this:
- Carbon (C): 1 × 3 = 3
- Hydrogen (H): 1.67 × 3 ≈ 5
- Nitrogen (N): 1 × 3 = 3
- Oxygen (O): 3 × 3 = 9
The empirical formula for nitroglycerin is C3H5N3O9.