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)

The correct option is ABC₃.

To find the empirical formula of compound X, we follow a step-by-step approach based on the percentage composition and atomic masses of the constituent elements A, B, and C.

Step 1: Determine the percentage of each element in the compound.
We are given:
Percentage of A = 32%
Percentage of B = 20%
The remaining percentage belongs to C. Since the total percentage must equal 100%:
Percentage of C = 100% - (Percentage of A + Percentage of B)
Percentage of C = 100% - (32% + 20%) = 100% - 52% = 48%

Step 2: Calculate the relative number of moles of each element.
To find the relative number of moles, we divide the percentage of each element by its respective atomic mass:
For A (Atomic mass = 64 u):
Relative moles of A = $\frac{32}{64}=0.5$
For B (Atomic mass = 40 u):
Relative moles of B = $\frac{20}{40}=0.5$
For C (Atomic mass = 32 u):
Relative moles of C = $\frac{48}{32}=1.5$

Step 3: Find the simplest molar ratio.
Divide the relative number of moles of each element by the smallest value among them (which is 0.5):
Ratio of A = $\frac{0.5}{0.5}=1$
Ratio of B = $\frac{0.5}{0.5}=1$
Ratio of C = $\frac{1.5}{0.5}=3$

Step 4: Write the empirical formula.
The simplest whole-number ratio of the elements A : B : C is 1 : 1 : 3. Therefore, the empirical formula of the compound X is A₁B₁C₃, which is written as ABC₃.