Question

How many grams of each of the following elements must be taken to get 1 mol of the element ?
(a) Sodium
(b) Chlorine
(c) Copper

• A. (a) 23 g, (b) 35.5 g, (c) 63.5 g.
• B. (a) 23 g, (b) 71 g, (c) 63.5 g.
• C. (a) 23 g, (b) 71 g, (c) 65 g.
• D. (a) 22 g, (b) 35.5 g, (c) 65 g.

Answer 1

Answer: (B)

(a) 23 g, (b) 71 g, (c) 63.5 g.

The atomic masses of sodium chlorine and copper are 23 g/mol, 35.5 g/mol and 63.5 g/mol respectively.
1 mole of sodium corresponds to 23 g.
1 mole of chloinre $C{l}_2$ corresponds to $2\times 35.5=71$ g.
1 mole of copper corresponds to 63.5 g.
Thus, 23 g, 71 g, 63.5 g of sodium, chlorine and copper must be taken to get 1 mol of each of the element.