October 15, 2019, 08:00:51 PM
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### Topic: Preparation of working solutions  (Read 315 times)

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#### MAK273

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##### Preparation of working solutions
« on: June 16, 2019, 09:15:08 AM »
Hi everyone. I need to prepare working solutions with specific concentrations; 0.001, 0.02, 0.04, 0.06, 0.08, 0.1mg/ml or very similar ones. The concentration of the stock solution is 1mg/ml. I know how to make serial dilutions but I just can't come up with these concentrations. Any idea? Is there any equation that I could use?
Many thanks

#### Borek

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##### Re: Preparation of working solutions
« Reply #1 on: June 16, 2019, 10:57:00 AM »
Hard to help not knowing where the problem is. Can you give an example of what you tried (and what didn't yield a result you want)?

http://www.chembuddy.com/?left=concentration&right=dilution-mixing
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

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##### Re: Preparation of working solutions
« Reply #2 on: June 17, 2019, 01:50:32 PM »
Use c1v1 = c2v2 where c1 is the concentration of your initial solution, v1 is the volume of the initial solution you will need to solve for, c2 is the concentration of the solution you want to make, and v2 is the volume of the solution you want to make.

For example, if you want to make 10 mL of 0.1 mg/mL, take

c1v1 = c2v2
1 mg/mL (v1) = (0.1mg/mL) (10mL)
v1 = 1 mL
Use 1 mL of your stock solution and 9 mL of your solvent.