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JAMB Chemistry 1981 Question 43

Question 43

Mole Concept and Stoichiometry

If 1 mole of aluminium contains 6 × 1023 atoms of aluminium, how many atoms are contained in 0.9 g of aluminium? (Al = 27)

  1. A.1.0 × 1021
  2. B.6.6 × 1021
  3. C.2.0 × 1022
  4. D.6.0 × 1022
  5. E.5.4 × 1023
Show the answer and explanation

Answer: C (2.0 × 1022)

Explanation

0.9 g ÷ 27 g/mol = 1/30 mol; 1/30 × 6 × 1023 = 2.0 × 1022 atoms.