Question

Find the no of molecules present in 0.6 grams of sodium chloride

Answer 1

Molar mass of Na, M = 23 g/mol

Given Mass, m = 0.6 g

Hence, No. of moles, n = 0.6/23

                                  = 0.02608

Hence, No of Molecules = n*Avogadro Number

                                        = 0.02608*6.022*10^23

                                      = 1.57 * 10^22 molecules

Answer 2

No.of molecules=no.of moles×N.A.

=(given mass÷mol.mass)×N.A.

=(0.6÷23)×6.022×10^23

=1.57×10^22