Question

We have 100 ml of 0.1 m kcl solution. to make it 0.2 m

Answer 1

   You cannot prepare a more concentrated solution from a lesser concentrated solution by dilution.

   We know the weight of KCl present in 100 ml of 0.1M KCl is= Mol.Wt/100 = 74.6/100= 0.746.

   So on adding exactly 0.746 g of KCl to exactly 100 ml of 0.1M KCl, we can get 0.2M KCl.