Question

Quantitative analysis of an organic compound (X) shows the following percentage composition.

C: 14.5% 
Cl: 64.46% 
H: 1.8%

Empirical formula mass of the compound (X) is:

Hint:

To determine the empirical formula, calculate the mole ratio of elements and find the simplest whole-number ratio.

Answer 1

Step 1: Calculate moles of each element:

\[ \text{Moles of C} = \frac{14.5}{12} = 1.21 \, \text{mol}, \quad \text{Moles of Cl} = \frac{64.46}{35.5} = 1.81 \, \text{mol}, \quad \text{Moles of H} = \frac{1.8}{1} = 1.8 \, \text{mol} \]

Step 2: Find the mole ratio by dividing each by the smallest number of moles (C).

\[ \text{C}: \frac{1.21}{1.21} = 1, \quad \text{Cl}: \frac{1.81}{1.21} = 1.5, \quad \text{H}: \frac{1.8}{1.21} = 1.49 \]

Step 3: The empirical formula is \( \text{C}_2\text{Cl}_3\text{H}_3 \), so the empirical formula mass is \( 2(12) + 3(35.5) + 3(1) = 146.5 \, \text{g/mol} \).

Final Conclusion: The empirical formula mass of the compound is approximately \( 146.5 \, \text{g/mol} \), which corresponds to \( 4.85 \times 10^1 \).