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

Correct Answer: 4.85

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): \[ C: \frac{1.21}{1.21} = 1, \quad Cl: \frac{1.81}{1.21} = 1.5, \quad H: \frac{1.8}{1.21} = 1.49 \] Step 3: The empirical formula is \( C_2Cl_3H_3 \), 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 \( 4.85 \times 10^1 \).