Question

What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44

Answer 1

Given :

Volume of stock solution, $V_s = 20\ mL$.

Volume of diluted solution, $V_d = 400 \ mL$.

Molarity of diluted solution, $M_d = 1.44\ M$.

To Find :

The concentration of the stock solution.

Solution :

We know, dilution factor is given by :

$D.F=\dfrac{V_ {diluted}}{V_{stock}}$      ....1)

and $D.F= \dfrac{M_{stock}}{M_{diluted}}$     ....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 :

$\dfrac{M_{stock}}{M_{diluted}} = 20\\\\M_{stock} = 20\times 1.44\\\\M_{stock} =28.8\ M$

The concentration of stock solution is nearest to 30 M.

Therefore, the correct option is 1) 30 M.