Question

Calculate the no. Of mole in 48g helium and 46g sodium atom

Answer 1

a) 48g of Helium  

Atomic mass of He = 4

Number of particles = Number of Moles x N     (Where N is Avogadro number)

= (given weight/ Gram atomic weight) x 6.023 x 10^23

= (4/48)x 6.023 x 10^23

= 6.023 x 10^23/12

= 0.5 x 10^23 Helium particles

∴ 48 g of He contains 12.046 x 10^23 moles.

b) 46g of Na atom

atomic mass of Na = 23

Number of particles = Number of Moles x N

= (given weight/ Gram atomic weight) x 6.023 x 10^23

= (46/23)x 6.023 x 10^23

= 2x 6.023 x 10^23

⇒12.046 x 10^23 Sodium particles

∴ 46 g of Na contains 12.046 x 10^23 moles.