Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 230 ml of a 74 % (w/v) solution to prepare 5 % w/v solution? |
| 2 | If 240 ml of a 20 % v/v solution is diluted to 2400 ml , what is the percent strength of the diluted solution? |
| 3 | If 810 ml of a 1 : 228 (w/v) solution is diluted to 2200 ml, what is the ratio strength of the new solution? |
| 4 | If 12 ml of a 0.10 % nasal spray was diluted with 12 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 44 % elixir can be prepared from 25 ml of a 49 % elixir? |
| 6 | If a cough syrup contains 6 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 4 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 350 ml of 30 % alcohol, 175 ml of 60 % alcohol, and 380 ml of 25 % alcohol? |
| 8 | A pharmacist combines 4 pints of a 5 % w/v povidone-iodine solution with 2 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 6 % and a 17 % solution do you need to prepare 3 gallon of 15 % solution? |
| 10 |
What proportion of 25 % zinc oxide and 85 % zinc oxide do you need to make 35 % zinc oxide? |
| 11 |
How many grams of 2 % hydrocortisone cream be mixed with 720 g of 0.75 % hydrocortisone cream to make a 1.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 3.25 L of 1: 2100 w/v solution to make a 1: 8000 w/v solution? |
| 13 |
How many grams of a 3.00 % 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
12 % 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 210 ml of 74 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 200 ml of water, 1300 ml of glycerin having a specific gravity of 1.25, and 1300 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.55 should be mixed with 4000 mL of a syrup having a specific gravity of 1.19 to obtain a product having a specific gravity of 1.26? |
Answers
The Answer to question 1 is: 3174.00 ml
The Answer to question 2 is: 2.00 % v/v
The Answer to question 3 is: 1 : 619
The Answer to question 4 is: 0.05 %
The Answer to question 5 is: 27.84 ml
The Answer to question 6 is: 168.00 mg
The Answer to question 7 is: 34 % v/v
The Answer to question 8 is: 7.50 % w/v
The Answer to question 9 is: 9290.45 ml of 17 % , 2064.55 ml of 6 %
The Answer to question 10 is: 5 : 1
The Answer to question 11 is: 1080.00 grams
The Answer to question 12 is: 9131.00 ml
The Answer to question 13 is: 5296.67 grams
The Answer to question 14 is: 80.13 ml
The Answer to question 15 is: 151.09 ml
The Answer to question 16 is: 1.03
The Answer to question 17 is: 965.52 ml