Question

A compound X contains 32% of A, 20% of B and remaining percentage of C. Then, the empirical formula of X is:
(Given atomic masses of A=64; B=40; C=32 u)

• A. A2BC2
• B. ABC3
• C. AB2C2
• D. ABC4

Answer 1

Answer: (B)

ABC3

Answer 2

Step 1: Calculate moles of each element:

Moles of A = $\frac{\text{Mass of A}}{\text{Atomic Mass of A}} = \frac{32}{64} = 0.5$

Moles of B = $\frac{\text{Mass of B}}{\text{Atomic Mass of B}} = \frac{20}{40} = 0.5$

Moles of C = $\frac{\text{Mass of C}}{\text{Atomic Mass of C}} = \frac{48}{32} = 1.5$

Step 2: Divide by smallest mole value:

Ratio: $\frac{0.5}{0.5} : \frac{0.5}{0.5} : \frac{1.5}{0.5} = 1 : 1 : 3$

Step 3: Empirical formula:

Empirical Formula: $ABC_3$