Determine the empirical formula of a compound found to contain the following 52.11% carbon, 13.14% hydrogen, and 34.75% oxygen
To determine the empirical formula of a compound, we need to calculate the relative number of atoms of each element in the compound.
Step 1: Convert the given percentages to grams.
To do this, assume we have 100 grams of the compound. Therefore, in 100 grams of the compound:
- Carbon: 52.11 grams
- Hydrogen: 13.14 grams
- Oxygen: 34.75 grams
Step 2: Convert the grams to moles.
To convert grams to moles, we need to divide the given mass (in grams) by the molar mass (in grams/mole) of each element.
The molar mass of carbon (C) = 12.01 g/mole
52.11 grams of carbon = 52.11 g / 12.01 g/mole = 4.337 moles of carbon
The molar mass of hydrogen (H) = 1.01 g/mole
13.14 grams of hydrogen = 13.14 g / 1.01 g/mole = 13.0 moles of hydrogen
The molar mass of oxygen (O) = 16.00 g/mole
34.75 grams of oxygen = 34.75 g / 16.00 g/mole = 2.172 moles of oxygen
Step 3: Divide each number of moles by the smallest number of moles.
To find the simplest whole-number ratio of the elements, divide the amount of each element's moles by the smallest number of moles calculated in Step 2 (in this case, oxygen).
Carbon: 4.337 moles / 2.172 moles = 1.998 ≈ 2
Hydrogen: 13.0 moles / 2.172 moles = 5.99 ≈ 6
Oxygen: 2.172 moles / 2.172 moles = 1
Step 4: Determine the empirical formula.
The empirical formula represents the simplest whole-number ratio of elements in a compound. Therefore, based on the calculations above, the empirical formula of the compound with 52.11% carbon, 13.14% hydrogen, and 34.75% oxygen is CH2O.