Question

(1) Avogadro's number is 6.02 x 10. Arrange the following samples in order of increasing number of carbon atoms: 12g C; 1 mol C2H2; 9 x 1023 molecules [ 12g C < 1 mol CH3 < 9 x 1023 molecules [2] 12g C < 9 x 10” molecules < 1 mol C2H2 [3] Imol CH3 < 12g PC < 9 x 102 molecules [4] 1 mol CH2 <9 x 10” molecules < 12g C [5] 9 x 10” molecules < 12g 2C < 1 mol C2H2

Answer 1

12 grams of ¹²C i.e no of moles => mass / molar mass => 12g / 12 g/mol => 1 mole

i.e 1 mole => 6.02*10²³ atoms

1 mol C2H2 i.e 1 mol contains the 2 atoms and then the total no of atoms are => 2 * 6.02*10²³ => 1.024*10²⁴ atoms

9*10²³ molecules means => 9*10²³ atoms are present

the increasing no of atoms are as follows

12 g of ¹²C < 9*10²³ < 1 mol C2H2

answer => [2]