Percentage Strength Volume in Volume Dilution Pharmacy Math Question

by Ray
(McKinleyville, CA, USA)

I am a math idiot and I'm sure this is probably an easy question but here it is. What is the percent strength of a solution that is made by adding 200mL of sterile water to 600mL of a 25% solution?

Comments for Percentage Strength Volume in Volume Dilution Pharmacy Math Question

Average Rating starstarstarstarstar

Click here to add your own comments

25% of volume is added to the solution; and percentage strength is diluted by 25%
by: David

First of all, thank you, Ray, for this question!

Next, we calculate the amount (in MG) of diluent in the solution:

25%/600ml = 150mg/600mL

Currently we have

150mg solute in 600mL solution.

Add the 200mL to the solution, which dilutes it...

150mg/800mL =

18.75% is the percentage strength of the newly diluted solution.

25% of 25% = 6.25%

25% - 25% = 18.75%

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Pharmacy Tech Math Questions.

Back to Home

[?]Subscribe To This Site
  • follow us in feedly
  • Add to My Yahoo!

Didn't find what you were looking for? Use the box below to search this entire site.

Custom Search

Recent Articles

  1. Pharmacy IV Math Question: Weight/Volume Dextrose in Water to Add to 500cc D10W

    Jun 21, 17 11:12 PM

    A pharmacist an IV which is 8% w/v dextrose in water. How many cc of pure sterile water should she add to 500cc of D10W to make the IV? I would appreciate

    Read More

  2. Dilute 1gm/5mL Cefazolin stock to 15mL of a 50mg/mL. How much diluent and stock solution is needed?

    Jun 21, 17 11:08 PM

    Prepare 15 mL of a 50 mg/mL cefazolin dilution from a stock of 1 g/5 mL. How many milliliters of diluent and stock solution will be needed?

    Read More

  3. Atrovent Inhalation Solution 0.02% 2.5ml Vials: What is the Qty for a 34 Days Supply?

    Jun 21, 17 11:03 PM

    Atrovent Inhalation solution 0.02%; 2.5 ml X2 vial dispense; 10 boxes 1 vial q.i.d 2 refills 34 days supply third party plan cover Qty___? ; refill____?;

    Read More