Question

Assume that you have 1, 2, 5, and 10 mL pipets and a 25 mL volumetric flask only. Describe in detail how you would prepare a solution with a concentration near 0.100 M from a 0.650 M stock solution using the glassware listed above. Calculate the final concentration of the diluted solution (it won't be exactly 0.100 M). It should be within 10% of 0.100 M. (Please see the Lab Skills for the accuracy on volumetric pipets and flasks.)

Answer 1

Step-by-step explanation:

The given data is as follows.

`V_(1)` = 25 ml,
`M_(1)` = 0.10 M

`V_(2)` = x ml =
`25 ml * (0.001 L)/(1 ml)`,
`M_(2)` = 0.650 M

It is known that relation between molarity and volume of two solutions is as follows.

`M_(1)V_(1)` =
`M_(1)V_(2)`

`0.10 M * 0.025 L` =
`0.650 * x`

x = 0.00385 L

or, = 3.85 ml

Since, this volume is closest to 4 ml so, we have to use a 2 ml pipette two times and then we have to put it in a 25 ml volumetric flask.

Hence, calculate the overall concentration as follows.

`M_(1)V_(1)` =
`M_(1)V_(2)`

`x * 0.025 L` =
`0.650 M * 0.004 L`

x = 0.104 M

Therefore, it is about 3.8% error that is lower than the required error.