Answer:
2.5 mL
Explanation:
The following data were obtained from the question:
Molarity of stock solution (M₁) = 2 M
Molarity of diluted solution (M₂) = 0.5 M
Volume of diluted solution (V₂) = 10 mL
Volume of stock solution needed (V₁) =?
Thus, we can obtain the volume of the stock solution needed by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
2 × V₁ = 0.5 × 10
2 × V₁ = 5
Divide both side by 2
V₁ = 5/2
V₁ = 2.5 mL
Thus, 2.5 mL of the stock solution is needed.
