Which of the following pairs have the same number of atoms ?
(i) 16 g of (g) and 4 g of (g)
(ii) 16 g of and 44 g of
(iii) 28 g of and 32 g of
(iv) 12 g of C (s) and 23 g of Na (s)
The answer are the options (iii) and (iv)
Explanation:
One mole is measured as the amount of a substance that has an equal number of atoms as contained in exactly 12 g of Carbon.
1 mole of C = 12g
While 23 grammes of Na (mass) = 1 mole of Na
28g N2 = 1 mole of nitrogen = 2 × atoms of nitrogen
= atoms of nitrogen
32g O2 = 1 mole of oxygen = atoms of oxygen