Answer:
150 mL
Step-by-step explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 10 M
Volume of diluted solution (V₂) = 3 L
Molarity of diluted solution (M₂) = 0.5 M
Volume of stock solution needed (V₁) =?
The volume of stock solution needed can be obtained as follow:
M₁V₁ = M₂V₂
10 × V₁ = 0.5 × 3
10 × V₁ = 1.5
Divide both side by 10
V₁ = 1.5 / 10
V₁ = 0.15 L
Finally, we shall convert 0.15 L to mL. This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.15 L = 0.15 L × 1000 mL / 1 L
0.15 L = 150 mL
Therefore, the volume of the stock solution needed is 150 mL