The empirical formula for a compound that is 48.7% C, 13.6% H and 37.8% N is ________.

Question

Quizplus · Accepted Answer

To determine the empirical formula, we need to convert the percentages to moles.

Assume we have 100g of the compound, then:
- The mass of C = 48.7g
- The mass of H = 13.6g
- The mass of N = 37.8g

Converting to moles:
- Moles of C = 48.7g / 12.01 g/mol = 4.05 mol 
- Moles of H = 13.6g / 1.008 g/mol = 13.5 mol
- Moles of N = 37.8g / 14.01 g/mol = 2.70 mol

Next, we need to find the simplest whole number ratio of C, H, and N. To do this, we divide each of the moles by the smallest number of moles (which is 2.70):
- C: 4.05 mol / 2.70 mol = 1.50 ≈ 1.5
- H: 13.5 mol / 2.70 mol = 5.00 ≈ 5
- N: 2.70 mol / 2.70 mol = 1

This gives us the empirical formula: C₁.₅H₅N

We can multiply through by 2 to get whole numbers: C₃H₁₀N₂, which is answer choice C.

The Empirical Formula for a Compound That Is 48