Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 90 ml of a 30 % (w/v) solution to prepare 17 % w/v solution? |
| 2 | If 435 ml of a 65 % v/v solution is diluted to 1300 ml , what is the percent strength of the diluted solution? |
| 3 | If 460 ml of a 1 : 106 (w/v) solution is diluted to 2500 ml, what is the ratio strength of the new solution? |
| 4 | If 24 ml of a 8.50 % nasal spray was diluted with 6 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 31 % elixir can be prepared from 15 ml of a 89 % elixir? |
| 6 | If a cough syrup contains 38 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 8 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 450 ml of 30 % alcohol, 250 ml of 60 % alcohol, and 190 ml of 25 % alcohol? |
| 8 | A pharmacist combines 8 pints of a 5 % w/v povidone-iodine solution with 10 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 7 % and a 16 % solution do you need to prepare 1 gallon of 11 % solution? |
| 10 |
What proportion of 10 % zinc oxide and 50 % zinc oxide do you need to make 40 % zinc oxide? |
| 11 |
How many grams of 4 % hydrocortisone cream be mixed with 440 g of 0.25 % hydrocortisone cream to make a 0.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 1.50 L of 1: 3400 w/v solution to make a 1: 6700 w/v solution? |
| 13 |
How many grams of a 6.00 % 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
29 % 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 230 ml of 74 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 400 ml of water, 1150 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 1.35 should be mixed with 4000 mL of a syrup having a specific gravity of 1.24 to obtain a product having a specific gravity of 1.32? |
Answers
The Answer to question 1 is: 68.82 ml
The Answer to question 2 is: 21.75 % v/v
The Answer to question 3 is: 1 : 576
The Answer to question 4 is: 6.80 %
The Answer to question 5 is: 43.06 ml
The Answer to question 6 is: 24.00 mg
The Answer to question 7 is: 37 % v/v
The Answer to question 8 is: 8.57 % w/v
The Answer to question 9 is: 1682.22 ml of 16 % , 2102.78 ml of 7 %
The Answer to question 10 is: 1 : 3
The Answer to question 11 is: 31.43 grams
The Answer to question 12 is: 1455.90 ml
The Answer to question 13 is: 1135.00 grams
The Answer to question 14 is: 62.07 ml
The Answer to question 15 is: 165.48 ml
The Answer to question 16 is: 1.04
The Answer to question 17 is: 10666.67 ml