JEE Main 2026 — Some Basic Concepts of Chemistry Question with Solution

For (A):

Formula of cyclohexane is $C_6{H}_{12}$.

Number of atoms per molecule = $6+12=18$.

Total number of atoms in $2$ moles = $2\times 18\times N_A=36N_A$.

For (B):

Formula of sucrose is $C_{12}{H}_{22}{O}_{11}$.

Molar mass of sucrose = $342$ g/mol.

Number of moles = $\frac{684}{342}=2$ moles.

Number of atoms per molecule = $12+22+11=45$.

Total number of atoms = $2\times 45\times N_A=90N_A$.

For (C):

Formula of dihydrogen is $H_2$.

Number of moles at STP = $\frac{90.8}{22.7}=4$ moles.

Number of atoms per molecule = $2$.

Total number of atoms = $4\times 2\times N_A=8N_A$.

Comparing the total number of atoms:

$90N_A>36N_A>8N_A$

Therefore, the correct order is $B>A>C$.

Answer: $B>A>C$