ratio, stock, stock solution

by Georgette
(Charleston, SC, USA)

How much of a 1:1000 stock is needed to make 360 ml of a 1:2400 solution?

Comments for ratio, stock, stock solution

Average Rating starstarstarstarstar

Click here to add your own comments

Rating
starstarstarstarstar
Answer: 3600mL of original stock solution and 150mg of solute
by: David

Thank you for the question, Georgette!

So we are starting with a 1:1000 stock solution, which is the same as = 0.1% Strength

We want to end up with a 360mL of a 1:2400 stock solution.

This is the same as a 0.0416% Strength.

How do we get to the answer?

We are going from a higher concentration (1:1000) to a lower concentration (1:2400).

The question now is, how much sterile water are we going to add to make this to the correct concentration?

In order to figure out how much diluent we will have at the end, we will multiply the volume (given, 360mL) by the percentage strength (given, 0.416%) which gives us 14.9999999, which we will round for simplicity's sake to 15mg.

So now we have some known variables and one unknown variable:

How much mixture (in mL) will we need at 0.1 percentage strength to equal 15mg in 360mL?

0.1% 15mg
------ = -----------
X mL 360 mL

Cross multiply...

360mL X 0.1% = X mL X 15mg

360mL X 10 = 15mL X XmL

3600 = 15mL X 240 mL

150mg 15mg
----- = ---------
3600 360

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
  • XML RSS
  • 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. 250mg/5mL Dispense 200mL Sig: 5mL q.i.d

    Dec 06, 17 11:16 PM

    How do you set this up to solve to find the days supply?

    Read More

  2. Days Supply Question: Neurontin 300mg 1 tablet po every other day #15

    Nov 27, 17 11:39 PM

    Neurontin 300 mg tablets #15 1 tab po qod What is the days supply?

    Read More

  3. Days Supply Question - Take One Tablet by Mouth Every 4 Hours As Needed for Pain Not To Exceed 6 Per Day

    Nov 27, 17 11:25 PM

    Take One Tablet by Mouth Every 4 Hours As Needed for Pain Not To Exceed 6 Per Day

    Read More

  4. Pharmacy Technician Cover Letters

    Nov 18, 17 07:44 PM

    Pharmacy Technician Cover Letters - The basic format to use when writing your Cover Letter, as well as what to write to make sure your resume gets moved into the "interview" pile.

    Read More

  5. Days Supply Question - #20 pills, 1.5 tablets by mouth daily

    Nov 18, 17 06:16 PM

    If you have 20 pills and you take 1.5 a days what's the days supply

    Read More

  6. Days Supply/Quantity for Stavudine (Zerit) prescription

    Nov 18, 17 06:05 PM

    Your pharmacy stocks stavudine in bottles of 30 capsules. How many capsules would you need to dispense for a 90 day supply?

    Read More

  7. Hospital Pharmacy Technician

    Nov 18, 17 02:17 AM

    Duties and Responsibilities of the Hospital Pharmacy Technician.

    Read More

  8. The Metric System for Pharmacy Technicians

    Nov 18, 17 01:20 AM

    This page discusses how Pharmacy Technicians use the Metric System of Measurement.

    Read More

  9. What is the days supply on Advair 250/50 #1 1 puff q12h?

    Nov 04, 17 10:37 PM

    What is the days supply on advair 250/50 #1 - 1 puff q12h?

    Read More

  10. Pharmacy Root Cause Analysis

    Oct 29, 17 10:40 PM

    Pharmacy Root Cause Analysis (RCA) - What is an RCA? How can it help PharmTechs and Save Lives?

    Read More

  11. Controlled Substance Pharmacy Technician

    Oct 29, 17 10:12 PM

    Controlled Substance Pharmacy Technician - Responsibilities, Qualifications, A Day in the Life, and Work Advantages

    Read More

  12. IV Infusion Calculations Explained

    Oct 29, 17 09:54 PM

    This page explains IV Infusion Calculations you may use in your job as a Pharmacy Technician.

    Read More

  13. Days Supply Question: Norco, #35 pills, 1 tablet every 4-6 hours

    Oct 29, 17 09:41 PM

    How many days should 35 Norco last me if I was given #35 at 1 every 4-6 hours?

    Read More

  14. Improving Pharmacy Safety Culture

    Oct 27, 17 08:01 PM

    This page discusses ways of Improving Pharmacy Safety Culture - Focusing on Work Environment, Processes and Procedures, not Personnel

    Read More

  15. How much dextrose is in D10W in a 250 bag?

    Oct 15, 17 04:54 PM

    In D10W, how much dextrose is in a 250mL bag?

    Read More