Among the following choose the ones with equal number of atoms. A. 212 g of Na_2 CO_3(~s) [molar mass =106 ~g ] B. 248 g of Na_2 O (s) [molar mass =62 ~g ] C. 240 g of NaOH(s) [molar mass =40 ~g] D. 12 g of H_2(~g)

Correct answer: B. A, B and D only No. of atoms = Atomicity × mole × N_ A (A) No. of atoms =6 × (212)/(106) × N_ A =12 ~N_ A (B) No. of atoms =3 × (248)/(62) × N_ A =12 ~N_ A (C) No. of atoms =3 × (240)/(40) × N_ A =18 ~N_ A (D) No. of atoms =2 × (12)/(2) × N_ A =12 ~N_ A (E) No. of atoms =3 × (220)/(44) × N_A=15 N_A

NEET 2025

Exam: NEET
Year: 2025
Subject: Chemistry
Chapter: Some Basic Concepts of Chemistry

NEET 2025 · Chemistry · Some Basic Concepts of Chemistry

Among the following choose the ones with equal number of atoms. A....

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:

Options

AA, B and C only
BA, B and D only
CB, C and D only
DB, D and E only

Correct answer

B. A, B and D only

Step-by-step 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}}

=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

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