Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 150 ml of a 60 % (w/v) solution to prepare 19 % w/v solution? |
| 2 | If 800 ml of a 5 % v/v solution is diluted to 2400 ml , what is the percent strength of the diluted solution? |
| 3 | If 825 ml of a 1 : 66 (w/v) solution is diluted to 1900 ml, what is the ratio strength of the new solution? |
| 4 | If 13 ml of a 0.30 % nasal spray was diluted with 14 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 29 % elixir can be prepared from 80 ml of a 86 % 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 3 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 350 ml of 30 % alcohol, 125 ml of 60 % alcohol, and 100 ml of 25 % alcohol? |
| 8 | A pharmacist combines 1 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 2 % and a 14 % solution do you need to prepare 3 gallon of 12 % solution? |
| 10 |
What proportion of 20 % zinc oxide and 45 % zinc oxide do you need to make 30 % zinc oxide? |
| 11 |
How many grams of 4 % hydrocortisone cream be mixed with 540 g of 0.25 % hydrocortisone cream to make a 1.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 3.75 L of 1: 1800 w/v solution to make a 1: 9900 w/v solution? |
| 13 |
How many grams of a 3.00 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 25 % w/w benzocaine ointment with white petrolatum? |
| 14 |
How many milliliters of a
24 % 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 180 ml of 46 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 500 ml of water, 900 ml of glycerin having a specific gravity of 1.25, and 1200 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.54 should be mixed with 4500 mL of a syrup having a specific gravity of 1.14 to obtain a product having a specific gravity of 1.16? |
Answers
The Answer to question 1 is: 323.68 ml
The Answer to question 2 is: 1.67 % v/v
The Answer to question 3 is: 1 : 152
The Answer to question 4 is: 0.14 %
The Answer to question 5 is: 237.24 ml
The Answer to question 6 is: 156.00 mg
The Answer to question 7 is: 36 % v/v
The Answer to question 8 is: 9.00 % w/v
The Answer to question 9 is: 9462.50 ml of 14 % , 1892.50 ml of 2 %
The Answer to question 10 is: 3 : 2
The Answer to question 11 is: 270.00 grams
The Answer to question 12 is: 16875.00 ml
The Answer to question 13 is: 3783.33 grams
The Answer to question 14 is: 27.78 ml
The Answer to question 15 is: 80.51 ml
The Answer to question 16 is: 1.00
The Answer to question 17 is: 236.84 ml