Answer:
0.28 L
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 18 M
Volume of diluted solution (V₂) = 2 L
Molarity of diluted solution (M₂) = 2.5 M
Volume of stock solution needed (V₁) =?
The volume of the stock solution needed can be obtained as follow:
M₁V₁ = M₂V₂
18 × V₁ = 2.5 × 2
18 × V₁ = 5
Divide both side by 18
V₁ = 5 / 18
V₁ = 0.28 L
Thus, the volume of the stock solution needed is 0.28 L
