search (google) for a 'percent to molarity calculator', determine what a 70% PCA stock is in terms of molarity (M), then run some C1V1 = C2V2. The 70% stock (in Molarity units) will be C1, C2 will be 0.5 M. Solve for either V1 or V2.

Aaron Dhanda - I followed your approach and I wanted to confirm that my approach was correct. I used this calculator: https://www.trimen.pl/witek/calculators/stezenia.html

70% PCA = 7 moles (7M)

Since I need to make a 10 mL 0.5M PCA solution:

• 7M x ___ = 0.5M x 10 mL
• 714 uL of 7M PCA + 9.286 mL sterile water

Hi Kristen, the C1V1 C2V2 math is correct, the 70% PCA = 7M, maybe double check what the density of PCA is, seems like you entered 1 for density in the calculator. Just double check that and change the density from 1 to whatever it is if its not 1. Then continue with the C1V1 C2V2 as you did.

Hi,

You may use the web tool to calculate

https://www.alfa-chemistry.com/solution-dilution-calculator.htm

https://www.alfa-chemistry.com/mass-molarity-calculator.htm