An organic compound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound is : [Atomic wt. of C is 12, H is 1]

The correct option is CH₃.

To find the empirical formula of the organic compound, we can follow these steps:

Step 1: Determine the percentage composition of each element.
The compound contains:
• Carbon (C) = 78% (by weight)
• Hydrogen (H) = Remaining percentage = 100% - 78% = 22% (by weight)

Step 2: Calculate the relative number of moles of each element.
We divide the percentage of each element by its respective atomic weight (Atomic weight of C = 12, H = 1):

$\text{Relative moles of C}=\frac{78}{12}=6.5$

$\text{Relative moles of H}=\frac{22}{1}=22$

Step 3: Find the simplest whole-number ratio.
We divide each relative mole value by the smallest value obtained (which is 6.5):

$\text{Ratio of C}=\frac{6.5}{6.5}=1$

$\text{Ratio of H}=\frac{22}{6.5}\approx 3.38\approx 3$

Since the simplest atomic ratio of C to H is approximately 1 : 3, the empirical formula of the compound is CH₃.