Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 260 ml of a 32 % (w/v) solution to prepare 5 % w/v solution? |
| 2 | If 890 ml of a 80 % v/v solution is diluted to 1400 ml , what is the percent strength of the diluted solution? |
| 3 | If 955 ml of a 1 : 204 (w/v) solution is diluted to 2100 ml, what is the ratio strength of the new solution? |
| 4 | If 15 ml of a 0.90 % nasal spray was diluted with 28 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 22 % elixir can be prepared from 65 ml of a 89 % elixir? |
| 6 | If a cough syrup contains 11 mg of a drug in each teaspoonful, how many mg of drug needs to be added to a 60 ml container of the syrup to make the concentration 10 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 250 ml of 40 % alcohol, 175 ml of 75 % alcohol, and 200 ml of 20 % alcohol? |
| 8 | A pharmacist combines 10 pints of a 5 % w/v povidone-iodine solution with 1 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 7 % and a 13 % solution do you need to prepare 2 gallon of 10 % solution? |
| 10 |
What proportion of 5 % zinc oxide and 55 % zinc oxide do you need to make 20 % zinc oxide? |
| 11 |
How many grams of 4 % hydrocortisone cream be mixed with 640 g of 0.5 % hydrocortisone cream to make a 1.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 4.50 L of 1: 800 w/v solution to make a 1: 8600 w/v solution? |
| 13 |
How many grams of a 9.00 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 35 % w/w benzocaine ointment with white petrolatum? |
| 14 |
How many milliliters of a
21 % w/v stock solution benzalkonium chloride
should be used in preparing the following prescription? |
| 15 |
How many milliliters of 85 % (w/w) lactic acid with a specific gravity of 1.21 be used to prepare 390 ml of 58 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 200 ml of water, 1350 ml of glycerin having a specific gravity of 1.25, and 1200 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.39 should be mixed with 7000 mL of a syrup having a specific gravity of 1.28 to obtain a product having a specific gravity of 1.30? |
Answers
The Answer to question 1 is: 1404.00 ml
The Answer to question 2 is: 50.86 % v/v
The Answer to question 3 is: 1 : 449
The Answer to question 4 is: 0.31 %
The Answer to question 5 is: 262.95 ml
The Answer to question 6 is: 468.00 mg
The Answer to question 7 is: 43 % v/v
The Answer to question 8 is: 5.83 % w/v
The Answer to question 9 is: 3785.00 ml of 13 % , 3785.00 ml of 7 %
The Answer to question 10 is: 7 : 3
The Answer to question 11 is: 106.67 grams
The Answer to question 12 is: 43875.00 ml
The Answer to question 13 is: 1765.56 grams
The Answer to question 14 is: 42.47 ml
The Answer to question 15 is: 219.93 ml
The Answer to question 16 is: 1.04
The Answer to question 17 is: 1555.56 ml