Q.How many molecules are contained in 0.35 mol of N2?

We know that 1 mole of any substance at NTP contains Avogadro’s number of molecules.

0.35 Mole of nitrogen contains = 0.35× 6.022 × 10 ²³ molecules of N₂ 

                                                            =2.17 × 10 ²³  molecules of N₂  Hence there are 2.17 × 10 ²³molecules of N₂ are present in 0.35 mol of N₂ .