Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 150 ml of a 86 % (w/v) solution to prepare 19 % w/v solution? |
| 2 | If 780 ml of a 25 % v/v solution is diluted to 2200 ml , what is the percent strength of the diluted solution? |
| 3 | If 625 ml of a 1 : 248 (w/v) solution is diluted to 800 ml, what is the ratio strength of the new solution? |
| 4 | If 16 ml of a 1.10 % nasal spray was diluted with 2 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 28 % elixir can be prepared from 35 ml of a 72 % elixir? |
| 6 | If a cough syrup contains 7 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 300 ml of 45 % alcohol, 250 ml of 65 % alcohol, and 330 ml of 15 % alcohol? |
| 8 | A pharmacist combines 6 pints of a 5 % w/v povidone-iodine solution with 5 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 6 % and a 10 % solution do you need to prepare 3 gallon of 9 % solution? |
| 10 |
What proportion of 10 % zinc oxide and 65 % zinc oxide do you need to make 35 % zinc oxide? |
| 11 |
How many grams of 3 % hydrocortisone cream be mixed with 100 g of 0.5 % hydrocortisone cream to make a 1.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 1.75 L of 1: 800 w/v solution to make a 1: 5300 w/v solution? |
| 13 |
How many grams of a 3.00 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 15 % w/w benzocaine ointment with white petrolatum? |
| 14 |
How many milliliters of a
19 % 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 480 ml of 76 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 700 ml of water, 850 ml of glycerin having a specific gravity of 1.25, and 1400 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.65 should be mixed with 6000 mL of a syrup having a specific gravity of 1.20 to obtain a product having a specific gravity of 1.51? |
Answers
The Answer to question 1 is: 528.95 ml
The Answer to question 2 is: 8.86 % v/v
The Answer to question 3 is: 1 : 317
The Answer to question 4 is: 0.98 %
The Answer to question 5 is: 90.00 ml
The Answer to question 6 is: 516.00 mg
The Answer to question 7 is: 39 % v/v
The Answer to question 8 is: 8.13 % w/v
The Answer to question 9 is: 8516.25 ml of 10 % , 2838.75 ml of 6 %
The Answer to question 10 is: 6 : 5
The Answer to question 11 is: 25.00 grams
The Answer to question 12 is: 9843.80 ml
The Answer to question 13 is: 2270.00 grams
The Answer to question 14 is: 13.32 ml
The Answer to question 15 is: 354.69 ml
The Answer to question 16 is: 0.98
The Answer to question 17 is: 13285.71 ml