Question

How to calculate the no.Of atoms in 100 g of n2 or 100g of nh3?

Answer 1

No. of moles of atoms = weight / atomic weight.

100 gms of N₂ = 100/2 x 14 moles = 100/28 moles

Number of molecules = 100 / 28 x 6.022 x 10²³

Molar mass of N₂ = 2 x molar mass of monoatomic  N

Molar mass of N₂ = 2 x 14.0067 = 28 moles.

Number of molecules = 100/28 x 6.022 x 10²³

No. of atoms = 2 x 100/28 x 6.022 x 10²³ = 43.01 x 10²³

For NH₃ :-

100 gm of NH₃ = 100/17 moles

Number of molecules = 100/17 x 6.022 x 10²³ molecules

No. of atoms in NH₃ = (1 + 3) = 4 x 100/17 x 6.022 x 10²³ =

141.69 x 10²³ atoms.