Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 60 ml of a 48 % (w/v) solution to prepare 21 % w/v solution? |
| 2 | If 205 ml of a 45 % v/v solution is diluted to 2000 ml , what is the percent strength of the diluted solution? |
| 3 | If 365 ml of a 1 : 90 (w/v) solution is diluted to 1000 ml, what is the ratio strength of the new solution? |
| 4 | If 40 ml of a 2.00 % nasal spray was diluted with 4 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 7 % elixir can be prepared from 85 ml of a 83 % 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 4 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 400 ml of 40 % alcohol, 125 ml of 50 % alcohol, and 240 ml of 15 % alcohol? |
| 8 | A pharmacist combines 6 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 6 % and a 11 % solution do you need to prepare 2 gallon of 8 % solution? |
| 10 |
What proportion of 25 % zinc oxide and 35 % zinc oxide do you need to make 30 % zinc oxide? |
| 11 |
How many grams of 3 % hydrocortisone cream be mixed with 640 g of 0.5 % hydrocortisone cream to make a 2.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 1.25 L of 1: 600 w/v solution to make a 1: 6500 w/v solution? |
| 13 |
How many grams of a 4.00 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 20 % w/w benzocaine ointment with white petrolatum? |
| 14 |
How many milliliters of a
13 % 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 320 ml of 62 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 700 ml of water, 1250 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 1.49 should be mixed with 3500 mL of a syrup having a specific gravity of 1.25 to obtain a product having a specific gravity of 1.47? |
Answers
The Answer to question 1 is: 77.14 ml
The Answer to question 2 is: 4.61 % v/v
The Answer to question 3 is: 1 : 247
The Answer to question 4 is: 1.82 %
The Answer to question 5 is: 1007.86 ml
The Answer to question 6 is: 156.00 mg
The Answer to question 7 is: 34 % v/v
The Answer to question 8 is: 8.50 % w/v
The Answer to question 9 is: 3028.00 ml of 11 % , 4542.00 ml of 6 %
The Answer to question 10 is: 1 : 1
The Answer to question 11 is: 960.00 grams
The Answer to question 12 is: 12291.70 ml
The Answer to question 13 is: 2270.00 grams
The Answer to question 14 is: 57.34 ml
The Answer to question 15 is: 192.90 ml
The Answer to question 16 is: 1.02
The Answer to question 17 is: 38500.00 ml