Question

no of ions present in 11.1g of calcium chloride

Answer 1

No. of moles = given mass / molar mass
                      = 11.1/111 = 0.1 moles
CaCl2 → Ca2+ + 2 Cl-
∴ 1 molecule gives 3 ions.
no. of molecules = no. of moles x Avagadro no. 
                           = 0.1 x 6.022 x 10^23  = 0.6023 x 10^23 molecules
∴ Total no. of ions = 3 x 0.6023 x 10^23 = 1.8069x10^23 ions