Question

Calculate the number of sulphate ions in 100mL of 0.001M H2SO4 solution.

Answer 1

1 mole of H2SO4 contains 1 mole of SO4(-2) ions


Number of moles of H2SO4 = volume in litres x molarity

                                             = (100/1000) x 0.001

                                             = 0.0001 moles


There are 0.0001 moles of suphate ions


Number of sulphate ions = number of ions x Avogadro’s Number
          
                                        = 0.0001 x 6.022 x10^23


                                        = 6.022 x 10^19

Answer 2

Explanation:

Ag3A = 3Ag + A

3 moles of Ag combine with 3 moles of A

Mass of Ag = 0.37

Mass of A = 607 - 0.37 = 606.63

Moles of Ag = 0.37/108 = 0.003426

Moles of A = 0.003426/3 = 0.001142

Molar mass of A = 606.63/0.001142 = 531211

A tribasic acid has 3 atom of H

Molar mass of the acid = 3 + 531211 = 531214 g/mol