Question

(a) What is Avogadro constant? 

(b) Calculate the number of particles present in 56 gm of N₂ molecule. 

Answer 1

(a) The number of atoms or molecules in 12 gm of carbon-12 ( in a mole of a substance) is called as Avogadro constant (6.022 × 10²³ ) 

(b) Number of molecules(N) = Given mass X Avgadros no / Molar mass

Molar mass of 1 mole of N₂= 14 × 2 =28 

N = 56/ 28 ×6.022 × 10²³ 

N = 12.044 × 10²³ 

Hence there are 12.044 × 10²³ particles present in 56 gm of N₂