Q63 / 180 · NEET 2025 · Chemistry
Among the following choose the ones with equal number of atoms.
A. 212 g of $\mathrm{Na}_2 \mathrm{CO}_3(\mathrm{~s})$ [molar mass $=106 \mathrm{~g}$ ]
B. 248 g of $\mathrm{Na}_2 \mathrm{O}$ (s) [molar mass $=62 \mathrm{~g}$ ]
C. 240 g of $\mathrm{NaOH}(\mathrm{s})$ [molar mass $=40 \mathrm{~g}]$
D. 12 g of $\mathrm{H}_2(\mathrm{~g})$ [molar mass $=2 \mathrm{~g}$ ]
E. 220 q of $\mathrm{CO}_2(\mathrm{q})$ [molar mass $\left.=44 \mathrm{~g}\right]$
Choose the correct answer from the options given below:
- AA, B and C only
- Correct answerBA, B and D only
- CB, C and D only
- DB, D and E only
Solution
No. of atoms $=$ Atomicity $\times$ mole $\times \mathrm{N}_{\mathrm{A}}$
(A) No. of atoms $=6 \times \frac{212}{106} \times \mathrm{N}_{\mathrm{A}}=12 \mathrm{~N}_{\mathrm{A}}$
(B) No. of atoms $=3 \times \frac{248}{62} \times \mathrm{N}_{\mathrm{A}}=12 \mathrm{~N}_{\mathrm{A}}$
(C) No. of atoms $=3 \times \frac{240}{40} \times \mathrm{N}_{\mathrm{A}}=18 \mathrm{~N}_{\mathrm{A}}$
(D) No. of atoms $=2 \times \frac{12}{2} \times \mathrm{N}_{\mathrm{A}}=12 \mathrm{~N}_{\mathrm{A}}$
(E) No. of atoms $=3 \times \frac{220}{44} \times N_A=15 N_A$
Hence, the correct answer is option: 'B'.