Aptos High School Global Health Odyssey
Health Professionals Use Math for Problem Solving


Pharmacist 3


Acids typically come in 95-98% concentrated form, to save storage space. Pharmacists almost never need the 95% variety, so they have to dilute it to the required concentration.

If you dilute to half water, the concentration will be 47.5 % acid. But how do you dilute it to a standard % like 50%?

You need to use a ratio of water to acid in different concentrations, then scale to different %.

Hint: 95% acid = 95 parts acid/100 parts total, with 5 parts water/100 parts total

So in this example, the ratio of water to acid = 5/95

In a 50/50 solution, the water/acid ratio must = 1

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