Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 120 ml of a 80 % (w/v) solution to prepare 12 % w/v solution? |
| 2 | If 530 ml of a 60 % v/v solution is diluted to 2100 ml , what is the percent strength of the diluted solution? |
| 3 | If 450 ml of a 1 : 328 (w/v) solution is diluted to 900 ml, what is the ratio strength of the new solution? |
| 4 | If 31 ml of a 0.50 % nasal spray was diluted with 22 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 22 % elixir can be prepared from 10 ml of a 43 % elixir? |
| 6 | If a cough syrup contains 2 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 9 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 300 ml of 35 % alcohol, 150 ml of 75 % alcohol, and 90 ml of 20 % alcohol? |
| 8 | A pharmacist combines 8 pints of a 5 % w/v povidone-iodine solution with 7 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 7 % and a 14 % solution do you need to prepare 1 gallon of 9 % solution? |
| 10 |
What proportion of 20 % zinc oxide and 50 % zinc oxide do you need to make 45 % zinc oxide? |
| 11 |
How many grams of 2 % hydrocortisone cream be mixed with 680 g of 0.5 % hydrocortisone cream to make a 1.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 2.00 L of 1: 1100 w/v solution to make a 1: 9700 w/v solution? |
| 13 |
How many grams of a 3.50 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 30 % 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 200 ml of 66 % (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 1000 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.40 should be mixed with 4000 mL of a syrup having a specific gravity of 1.11 to obtain a product having a specific gravity of 1.20? |
Answers
The Answer to question 1 is: 680.00 ml
The Answer to question 2 is: 15.14 % v/v
The Answer to question 3 is: 1 : 656
The Answer to question 4 is: 0.29 %
The Answer to question 5 is: 19.55 ml
The Answer to question 6 is: 516.00 mg
The Answer to question 7 is: 44 % v/v
The Answer to question 8 is: 8.18 % w/v
The Answer to question 9 is: 1081.43 ml of 14 % , 2703.57 ml of 7 %
The Answer to question 10 is: 1 : 5
The Answer to question 11 is: 340.00 grams
The Answer to question 12 is: 15636.40 ml
The Answer to question 13 is: 3891.43 grams
The Answer to question 14 is: 46.30 ml
The Answer to question 15 is: 128.34 ml
The Answer to question 16 is: 1.05
The Answer to question 17 is: 1800.00 ml