Question

Explain how you would prepare a 5 M solution of sulfuric acid from 100mL 18 M H2SO4. Show all necessary work.

Answer 1

Let us consider that we have to prepare 100 mL of 5M solution from 18M sulfuric acid solution.

According to law of dilution   MV = M'V'

Where M = Molarity of stock solution = 18 M

V = Volume of the stock solution taken = ?

M' = Molarity of dilute solution = 5M

V' = Volume of the dilute solution = 100 mL

Plug the values we get   , V = M'V' /M

                                         = ( 5 x 100 ) / 18

                                         = 27.8 mL

Therefore the volume of 18M solution taken is 27.8 mL

Therefore the volume of water added is = V' - V

                                                        = 100 mL - 27.8 mL

                                                       = 72.2 mL of water

Preparation procedure:-

Take 72.2 mL of water in a beaker & kept it in a water -bath.To this add 27.8 mL of 18 M H₂SO₄ solution drop-wise by continuous stirring.Then the resultent solution is the required solution.