Question

convert into mole (i) 20g of water ( atomic mass of hydrogen and oxygen are 1 and 16 respectively

Answer 1

Molar mass of H2O = 2 x 1 + 16 = 18g

Number of moles in 20 g H2O = 20/18
= 1.11mole
20g moles=1.11moles

Answer 2

Molar mass of H2O =2×1+16

                                = 18g

Number of moles in 20g H2O=20/18  

                                                  =1.11

     20g moles =1.11