Question

The molar mass of Allura red is 496 g/mol. The stock solution contains 93.84 mg/L Allura red. ac. To create 100.00 mL of a 1.89 x 10-6 M solution, you would need this many _____ mL of the stock solution.

Answer 1

Answer: The required stock solution for the preparation of dilute solution is 1.0 ml.

Explanation:

First, we will calculate the molarity of given solution as follows.

         Molarity = $\frac{mass}{\text{molar mass}}$

                       = $\frac{93.84 \times 10^{-3}g}{496 g}$

                       = $0.1892 \times 10^{-3} mol/L$

                       = $1.892 \times 10^{-4} mol/L$

Also, we know that

                  $M_{1}V_{1} = M_{2}V_{2}$

   $1.89 \times 10^{-6} \times V_{1} = 1.892 \times 10^{-4} \times 100 ml$

               $V_{1}$ = 1.0 ml

Thus, we can conclude that the required stock solution for the preparation of dilute solution is 1.0 ml.