- Empirical Formula: $C_4H_9$

- Molecular Mass: 114 grams/mole

Step 1: Determine the empirical formula mass

The empirical formula mass is the sum of the atomic masses of the elements in the empirical formula.

$C_4H_9$

4 (12.01 g mol^-1) + 9 (1.01 g mol^-1)

$=(4 × 12.01) (9 × 1.01) g/mol$

=48.04 + 9.09 g/mol

Empirical Formula Mass = 57.13 g/mole

Step 2: Calculate the molecular formula

The molecular formula is a multiple of the empirical formula.

$$ n=\frac{\text{Molecular mass}}{\text{Empirical formula mass}}$$

$$ =\frac{\text{114 g/mole}}{\text{57.13 g/mole}}=2$$

So the molecular formula is twice the empirical formula:

$$ (C_4H_9) *2 = C_8H_{18}$$

Molecular Formula: \(C_8H_{18}\)