Question

If 1.8 L of water is added to 2.5 L of a 7.0 M KOH solution, what is the molarity of the new solution?

Answer 1

Molarity= (number of moles of that substance) / (Volume of solution in litres)

7= (number of moles of HCl) / 0.05

Thus,

Number of moles of HCl = 7 x 0.05 = 0.35

The number of moles of HCl will remain unchanged.

Now, for new solution,

0.35= 0.35 / (New volume of solution in litres)

Thus,

New volume = 1 litre

Thus, amount of water added = 1- 0.05 litre = 5.0 M