Question

What volume of a 2.5 M stock solution of acetic acid is required to prepare 100.0 milliliters of a .50 M acetic acid solution?

Answer 1

`20. "milliliters"` of acetic acid is required

Explanation:

Whenever you are dealing with a dilution, (going from a higher concentration to a lower concentration), you can use the equation below:

Let's determine our known and unknown variables:

`color(blue)("Knowns:"`

• Initial Molarity
• Final Volume
• Final Molarity

`color(orange)("Unknowns:"`

• Initial Volume

Next, we rearrange the equation to solve for `V_1` by dividing by `M_1` on both sides of the equation:

`V_1=(M_2xxV_2)/M_1`

Plug in the known values and solve for your unknown:
`V_1=(0.50cancel"M"xx100.0mL)/(2.5cancel"M")`

Therefore,

`V_1 = 20. mL`