Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 110 ml of a 44 % (w/v) solution to prepare 22 % w/v solution? |
| 2 | If 500 ml of a 90 % v/v solution is diluted to 1200 ml , what is the percent strength of the diluted solution? |
| 3 | If 425 ml of a 1 : 70 (w/v) solution is diluted to 1700 ml, what is the ratio strength of the new solution? |
| 4 | If 24 ml of a 0.10 % nasal spray was diluted with 10 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 9 % elixir can be prepared from 80 ml of a 14 % elixir? |
| 6 | If a cough syrup contains 10 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 3 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 200 ml of 45 % alcohol, 175 ml of 55 % alcohol, and 50 ml of 15 % alcohol? |
| 8 | A pharmacist combines 7 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 7 % and a 10 % solution do you need to prepare 4 gallon of 8 % solution? |
| 10 |
What proportion of 15 % zinc oxide and 40 % zinc oxide do you need to make 20 % zinc oxide? |
| 11 |
How many grams of 4 % hydrocortisone cream be mixed with 660 g of 0.25 % hydrocortisone cream to make a 1.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 4.50 L of 1: 2600 w/v solution to make a 1: 6800 w/v solution? |
| 13 |
How many grams of a 4.00 % 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
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 650 ml of 52 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 100 ml of water, 1100 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 1.43 should be mixed with 3500 mL of a syrup having a specific gravity of 1.19 to obtain a product having a specific gravity of 1.31? |
Answers
The Answer to question 1 is: 110.00 ml
The Answer to question 2 is: 37.50 % v/v
The Answer to question 3 is: 1 : 280
The Answer to question 4 is: 0.07 %
The Answer to question 5 is: 124.44 ml
The Answer to question 6 is: 60.00 mg
The Answer to question 7 is: 46 % v/v
The Answer to question 8 is: 6.82 % w/v
The Answer to question 9 is: 5046.67 ml of 10 % , 10093.33 ml of 7 %
The Answer to question 10 is: 4 : 1
The Answer to question 11 is: 330.00 grams
The Answer to question 12 is: 7269.20 ml
The Answer to question 13 is: 3405.00 grams
The Answer to question 14 is: 41.55 ml
The Answer to question 15 is: 328.63 ml
The Answer to question 16 is: 1.04
The Answer to question 17 is: 3500.00 ml