The chemical analysis of aspirin indicates that the molecule is 60.00% carbon, 4.44% hydrogen, and 35.56% oxygen. What is the emperical formula for asprin?
Easy. Assume you have 100 g of the substance, so you have
60g C = 60/12 moles C= 5 mol C
4.44gH = 4.44/1= 4.44 mol H
35.56g O = 35.55/16 mol= 2.22 mol O
We want a whole number ratio, so divide all three of those moles by the lowest.
2.25 mol C
2Mole H
1 mol O
That is still not whole number, so we can get a whole number ratio by multiplying by 4
9 mol C
8 mol H
4 mol O
Empirical Formula:
C9 H8 O4
Could it really be aspirin?
Well, it seems our friend aspirin is made up of quite a few atoms. With 60.00% carbon, 4.44% hydrogen, and 35.56% oxygen, we can't just call it "Spicylicious." We need an empirical formula! Now, I would normally use some clown magic to make one up, but this time, I'll do my mathemagic.
So, let's say we have 100 grams of aspirin. That means we have 60 grams of carbon, 4.44 grams of hydrogen, and 35.56 grams of oxygen. Now, let's convert these grams into moles to make it easier on us.
The atomic mass of carbon is approximately 12 grams/mol, so 60 grams of carbon is equal to 60/12 = 5 moles.
Similarly, the atomic mass of hydrogen is about 1 gram/mol, so 4.44 grams of hydrogen is equal to 4.44/1 = 4.44 moles.
Lastly, the atomic mass of oxygen is around 16 grams/mol, so 35.56 grams of oxygen is equal to 35.56/16 = 2.22 moles.
Now, we have the mole ratios. Let's divide each number of moles by the smallest number of moles, which is 2.22 (oxygen).
Carbon: 5 moles/2.22 moles = 2.25 (approximately)
Hydrogen: 4.44 moles/2.22 moles = 2.00
Oxygen: 2.22 moles/2.22 moles = 1.00
So, our simplified empirical formula for aspirin is C2.25H2O. But since we can't have a fraction in a formula, we'll multiply everything by 4 to get whole numbers.
Therefore, the empirical formula for aspirin is C9H8O4! Ta-da!
Just remember, it's empirical, not empirical-clownical!
To determine the empirical formula of aspirin, we need to convert the percentages to moles. We assume that we have 100 g of the compound, which means we have 60.00 g of carbon, 4.44 g of hydrogen, and 35.56 g of oxygen.
Next, we need to find the moles of each element by using their molar masses. The molar mass of carbon (C) is 12.01 g/mol, hydrogen (H) is 1.01 g/mol, and oxygen (O) is 16.00 g/mol.
Moles of carbon:
moles of carbon = mass of carbon ÷ molar mass of carbon
moles of carbon = 60.00 g ÷ 12.01 g/mol ≈ 4.998 mol ≈ 5 mol (rounded to the nearest whole number)
Moles of hydrogen:
moles of hydrogen = mass of hydrogen ÷ molar mass of hydrogen
moles of hydrogen = 4.44 g ÷ 1.01 g/mol ≈ 4.396 mol ≈ 4 mol (rounded to the nearest whole number)
Moles of oxygen:
moles of oxygen = mass of oxygen ÷ molar mass of oxygen
moles of oxygen = 35.56 g ÷ 16.00 g/mol ≈ 2.222 mol ≈ 2 mol (rounded to the nearest whole number)
Thus, the empirical formula for aspirin is C5H4O2.
To determine the empirical formula of aspirin, we need to find the simplest whole-number ratio of atoms in the compound based on the given percentage composition.
1. Start by assuming we have a 100g sample of aspirin. This will allow us to calculate the grams of each element present in the compound.
Carbon: 60.00% of 100g = 60g
Hydrogen: 4.44% of 100g = 4.44g
Oxygen: 35.56% of 100g = 35.56g
2. Convert the grams of each element to moles using their respective atomic masses:
Carbon (C): atomic mass = 12.01 g/mol
Hydrogen (H): atomic mass = 1.01 g/mol
Oxygen (O): atomic mass = 16.00 g/mol
Moles of carbon = 60g / 12.01 g/mol ≈ 4.996 mol
Moles of hydrogen = 4.44g / 1.01 g/mol ≈ 4.396 mol
Moles of oxygen = 35.56g / 16.00 g/mol ≈ 2.222 mol
3. Calculate the ratio of moles by dividing each value by the smallest value:
Carbon: 4.996 mol / 2.222 mol ≈ 2.25
Hydrogen: 4.396 mol / 2.222 mol ≈ 1.98
Oxygen: 2.222 mol / 2.222 mol = 1.00
4. Round the ratio to the nearest whole number to get the empirical formula:
Carbon: 2.25 ≈ 2
Hydrogen: 1.98 ≈ 2
Oxygen: 1.00 = 1
Therefore, the empirical formula of aspirin is C2H2O.