how many mL of the 3.50 M stock solution of acetic acid is required to prepare
The correct answer and explanation is:
To answer the question properly, I need to know the volume and concentration of the diluted acetic acid solution you want to prepare. Since the question seems incomplete, I will assume a common case:
Example Question:
How many milliliters (mL) of a 3.50 M stock solution of acetic acid are required to prepare 500.0 mL of 0.875 M acetic acid?
Correct Answer:
125.0 mL of the 3.50 M stock solution is needed.
Explanation (300 words):
When preparing a solution from a more concentrated stock, the dilution formula is used. This formula is:
M₁V₁ = M₂V₂
Where:
- M₁ is the concentration of the stock solution
- V₁ is the volume of the stock solution to use
- M₂ is the desired concentration of the final solution
- V₂ is the desired volume of the final solution
In this case, we are given:
- M₁ = 3.50 M (stock solution)
- M₂ = 0.875 M (desired concentration)
- V₂ = 500.0 mL (final volume)
We need to find V₁.
Substitute into the formula:
3.50 × V₁ = 0.875 × 500.0
3.50 × V₁ = 437.5
Now divide both sides by 3.50:
V₁ = 437.5 ÷ 3.50
V₁ = 125.0 mL
So, to make 500.0 mL of 0.875 M acetic acid, you need to measure out 125.0 mL of the 3.50 M stock solution and then add enough water to reach a final volume of 500.0 mL.
This process is called dilution, and it is based on the principle of conservation of moles of solute. The number of moles of acetic acid in the concentrated solution stays the same after it is diluted, but the volume increases, which lowers the concentration. This is a key technique in laboratory preparation of solutions.