Question

The total number of ions present in 111 g of $CaC{l}_2$ is:

• A. one mole
• B. two mole
• C. four mole
• D. three mole

Answer 1

The correct option is D three mole

Molecular weight of $CaC{l}_2=111g/mol$

Ions in one calcium chloride molecule = $C{a}^{+2}+2C{l}^{-}$ = 3 ions

Now no. of molecules in $111g/mol$ of $CaC{l}_2$ = Avogadro's number
= $6.02\times {10}^{23}$ molecules

So number of ions in $111g/mol$ of $CaC{l}_2=3\times 6.02\times {10}^{23}$ ions $=3$ moles.