Question

Give all the steps necessary to obtain 100 mL of a 1.9 X 10 -5 M solution using serial dilution. The required laboratory equipment and compound information are given:0.15 grams of a compound with a molar mass of 793 g/mol, deionized water, 1.0 mL pipette, 5.0 mL pipette, 10.0 mL pipette and two - 100.0 mL volumetric flasks

Answer 1

Answer:

Take 10.0mL of stock solution using 10.0mL pipette in a 100mL volumetric flask and make up the solution with deionized water up to the mark of the flask and we get 100mL of 1.9×10⁻⁵M solution.

Explanation:

Molarity of stock solution, $M = \frac{mass}{Molar mass} * \frac{1}{Volume (L)}$

$M = \frac{0.15g}{793mol^{-1}} * \frac{1}{1.0L} = 1.9*10^{-4}M$

According to law of dilution MV = m'v'

Where, M = Molarity of stock solution = 1.9×10⁻⁴M

            V = Volume of stock solution = ?

            m' = Molarity of dilute solution = 1.9×10⁻⁵M

            v' = Volume of dilute solution = 100 mL

Substituting the above parameters in the equation of dilution

  $V = \frac{m'v'}{M}$

  $V = 10.0 mL$