Question

Stock solutions are highly concentrated solutions regularly made in laboratories to reduce preparation time and must be diluted down accordingly before use. While preparing a liquid media, the recipe you are following calls for a 1M media solution. Luckily, you made a 10M stock of this media solution beforehand. If the recipe requires 100mL of the stock solution, how many liters of water must you mix with the media solution to dilute it to the needed concentration

Answer 1

To dilute the 10M stock solution to a 1M media solution, you will need to mix it with 900mL of water.

Step-by-step explanation:

To dilute the 10M stock solution to a 1M media solution, you will need to mix it with water. Let's calculate the volume of water needed:

1M stock solution * volume of stock solution = 1M diluted solution * (volume of stock solution + volume of water)

100mL * volume of stock solution = 1M * (100mL + volume of water)

Volume of water = (100mL * volume of stock solution) - 100mL

Since you are starting with 10M stock solution, the volume of water needed will be: (100mL * 10) - 100mL = 900mL.

Answer 2

0.9 L.

Step-by-step explanation:

The following data were obtained from the question:

Molarity of stock solution (M1) = 10 M

Molarity of diluted solution (M2) = 1 M

Volume of stock solution (V1) = 100 mL

Volume of water needed =.?

Next, we shall determine the volume of the diluted solution. This can be obtained as follow:

Molarity of stock solution (M1) = 10 M

Molarity of diluted solution (M2) = 1 M

Volume of stock solution (V1) = 100 mL

Volume of diluted solution (V2) =.?

M1V1 = M2V2

10 × 100 = 1 × V2

1000 = V2

V2 = 1000 mL

Next, we shall determine the volume of water needed. This can be obtained as follow:

Volume of stock solution (V1) = 100 mL

Volume of diluted solution (V2) = 1000 mL

Volume of water needed =?

Volume of water needed = (Volume of diluted solution) – (Volume of stock solution)

Volume of water needed = V2 – V1

Volume of water needed = 1000 – 100

Volume of water needed = 900 mL

Finally, we shall convert 900 mL to litre (L). This can be obtained as follow:

1000 mL = 1 L

Therefore,

900 mL = 900 mL × 1 L / 1000 mL

900 mL = 0.9 L

Therefore, the volume of water needed to dilute the solution is 0.9 L.