True or False? to prepare 20.0 mL of a 2.00 M solution of hydrochloric acid from a 10.0M stock solution, you should take 4.00 mL of the stock solution and add 20.0 mL of water. Explain your answer

asked by @keenap1 • 10 months ago • Chemistry • 5 pts
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Hi @keenap1! When we prepare diluted solutions, we have to stick on the volume of the desired diluted sample. In this example, we need to prepare 20 mL of 2 M solution however it was suggested to add 20 mL of water with 4 mL 10M HCl which results to a volume of 24 mL which is incorrect. So the answer is false.

Using the dilution formula, we can get volume of 10M needed for a 2 M solution.

C1V1=C2V2

(20mL)(2M)=(10M)V2

V2=(40/10)

V2=4 mL of 10M HCl

Meaning we have to put 16 mL of water with 4 mL of HCl to get 20 mL of 2M solution. Not 20 mL of water in 4 mL 10M HCl.

I hope that makes sense!

answered by @reyn • 10 months ago