Final answer:
To find the empirical formula, convert the mass percentages to moles, find the simplest whole number ratio, and construct the formula. In this case, the empirical formula of the organic compound is C4H4NO.
Step-by-step explanation:
To find the empirical formula of an organic compound containing carbon, hydrogen, nitrogen, and oxygen, we start by assuming a 100 g sample, which converts the percentage composition directly into grams. The student has provided the percentages of carbon (C), hydrogen (H), and nitrogen (N), which are 61.71%, 4.03%, and 16.00% respectively. Since oxygen was not provided, we can calculate it by subtracting the sum of C, H, and N percentages from 100%.
Let's calculate the percentages for each element:
- For Carbon: 61.71% C
- For Hydrogen: 4.03% H
- For Nitrogen: 16.00% N
- For Oxygen: 100% - (61.71% + 4.03% + 16.00%) = 18.26% O
Next, we convert these percentages into moles by dividing by the respective atomic masses:
- C: (61.71 g / 12.01 g/mol) = 5.14 moles
- H: (4.03 g / 1.008 g/mol) = 4.00 moles
- N: (16.00 g / 14.01 g/mol) = 1.14 moles
- O: (18.26 g / 16.00 g/mol) = 1.14 moles
To determine the simplest whole number ratio, we divide each mole value by the smallest number of moles calculated, which is 1.14 moles:
- C: 5.14 moles / 1.14 moles = 4.51 ≈ 4
- H: 4.00 moles / 1.14 moles = 3.51 ≈ 4
- N: 1.14 moles / 1.14 moles = 1
- O: 1.14 moles / 1.14 moles = 1
The empirical formula is therefore C4H4N1O1, or more simply put, C4H4NO.