Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 60 ml of a 62 % (w/v) solution to prepare 3 % w/v solution? |
| 2 | If 620 ml of a 80 % v/v solution is diluted to 2400 ml , what is the percent strength of the diluted solution? |
| 3 | If 510 ml of a 1 : 224 (w/v) solution is diluted to 1800 ml, what is the ratio strength of the new solution? |
| 4 | If 44 ml of a 1.10 % nasal spray was diluted with 30 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 15 % elixir can be prepared from 55 ml of a 72 % elixir? |
| 6 | If a cough syrup contains 40 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 9 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 200 ml of 40 % alcohol, 225 ml of 70 % alcohol, and 330 ml of 20 % 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 5 % and a 11 % solution do you need to prepare 2 gallon of 9 % solution? |
| 10 |
What proportion of 20 % zinc oxide and 70 % zinc oxide do you need to make 25 % zinc oxide? |
| 11 |
How many grams of 5 % hydrocortisone cream be mixed with 440 g of 0.25 % hydrocortisone cream to make a 4.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 2.00 L of 1: 2400 w/v solution to make a 1: 7600 w/v solution? |
| 13 |
How many grams of a 8.00 % 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
21 % 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 260 ml of 50 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 600 ml of water, 600 ml of glycerin having a specific gravity of 1.25, and 1100 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.41 should be mixed with 7500 mL of a syrup having a specific gravity of 1.09 to obtain a product having a specific gravity of 1.10? |
Answers
The Answer to question 1 is: 1180.00 ml
The Answer to question 2 is: 20.67 % v/v
The Answer to question 3 is: 1 : 791
The Answer to question 4 is: 0.65 %
The Answer to question 5 is: 264.00 ml
The Answer to question 6 is: 60.00 mg
The Answer to question 7 is: 40 % v/v
The Answer to question 8 is: 8.50 % w/v
The Answer to question 9 is: 5046.67 ml of 11 % , 2523.33 ml of 5 %
The Answer to question 10 is: 9 : 1
The Answer to question 11 is: 3740.00 grams
The Answer to question 12 is: 4333.30 ml
The Answer to question 13 is: 851.25 grams
The Answer to question 14 is: 61.90 ml
The Answer to question 15 is: 126.40 ml
The Answer to question 16 is: 0.97
The Answer to question 17 is: 241.94 ml