What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44 M solution?
30 M
40 M
50 M
5M

Given :

Volume of stock solution, .

Volume of diluted solution, .

Molarity of diluted solution, .

To Find :

The concentration of the stock solution.

Solution :

We know, dilution factor is given by :

     ....1)

and     ....2)

Putting volume in above equation, we get :

D.F = 400/20

D.F = 20

Putting value of D.F in equation 2) we get :

The concentration of stock solution is nearest to 30 M.

Therefore, the correct option is 1) 30 M.

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