Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 210 ml of a 56 % (w/v) solution to prepare 24 % w/v solution? |
| 2 | If 745 ml of a 35 % v/v solution is diluted to 2500 ml , what is the percent strength of the diluted solution? |
| 3 | If 720 ml of a 1 : 366 (w/v) solution is diluted to 1300 ml, what is the ratio strength of the new solution? |
| 4 | If 29 ml of a 0.70 % nasal spray was diluted with 8 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 46 % elixir can be prepared from 60 ml of a 72 % elixir? |
| 6 | If a cough syrup contains 26 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 6 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 300 ml of 35 % alcohol, 100 ml of 65 % alcohol, and 170 ml of 15 % alcohol? |
| 8 | A pharmacist combines 2 pints of a 5 % w/v povidone-iodine solution with 4 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 3 % and a 17 % solution do you need to prepare 3 gallon of 13 % solution? |
| 10 |
What proportion of 25 % zinc oxide and 45 % zinc oxide do you need to make 40 % zinc oxide? |
| 11 |
How many grams of 5 % hydrocortisone cream be mixed with 200 g of 0.75 % hydrocortisone cream to make a 4.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 1.75 L of 1: 500 w/v solution to make a 1: 8300 w/v solution? |
| 13 |
How many grams of a 7.50 % 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
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 600 ml of 58 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 500 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 7000 mL of a syrup having a specific gravity of 1.27 to obtain a product having a specific gravity of 1.33? |
Answers
The Answer to question 1 is: 280.00 ml
The Answer to question 2 is: 10.43 % v/v
The Answer to question 3 is: 1 : 661
The Answer to question 4 is: 0.55 %
The Answer to question 5 is: 93.91 ml
The Answer to question 6 is: 48.00 mg
The Answer to question 7 is: 34 % v/v
The Answer to question 8 is: 9.00 % w/v
The Answer to question 9 is: 8110.71 ml of 17 % , 3244.29 ml of 3 %
The Answer to question 10 is: 1 : 3
The Answer to question 11 is: 1500.00 grams
The Answer to question 12 is: 27300.00 ml
The Answer to question 13 is: 2118.67 grams
The Answer to question 14 is: 38.51 ml
The Answer to question 15 is: 338.36 ml
The Answer to question 16 is: 1.05
The Answer to question 17 is: 6000.00 ml