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Atoms and Molecules — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceAtoms and Molecules1 Mark
MCQ
16g of S8 molecules contain:
  • A
    3.78 × 1022 atoms.
  • B
    3.78 × 1022 × 8 atoms.
  • C
    3.78 × 1022 moles.
  • D
    3.78 × 1023 molecules.
✓

Answer

  1. 3.78 × 1023 molecules.

Explanation:

Molar mass of S8 = 256g mol-1

We know,

1 mole of S8 = Molar mass of S8 = 6.022 × 1023 molecules.

256g of S8 = 6.022 × 1023 molecules.

Hence, 16g of S8 $=\frac{6.022\times10^{23\times}16}{256}$ molecules

= 3.76 × 1022 molecules

= 3.76 × 1022 molecules

= 3.78 × 1023 molecules (approx)

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