Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 110 ml of a 38 % (w/v) solution to prepare 1 % w/v solution? |
| 2 | If 345 ml of a 15 % v/v solution is diluted to 800 ml , what is the percent strength of the diluted solution? |
| 3 | If 210 ml of a 1 : 186 (w/v) solution is diluted to 1900 ml, what is the ratio strength of the new solution? |
| 4 | If 9 ml of a 0.90 % nasal spray was diluted with 14 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 49 % elixir can be prepared from 35 ml of a 89 % elixir? |
| 6 | If a cough syrup contains 23 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 10 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 200 ml of 40 % alcohol, 150 ml of 75 % alcohol, and 80 ml of 10 % alcohol? |
| 8 | A pharmacist combines 3 pints of a 5 % w/v povidone-iodine solution with 3 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 3 % and a 9 % solution do you need to prepare 4 gallon of 4 % solution? |
| 10 |
What proportion of 5 % zinc oxide and 90 % zinc oxide do you need to make 65 % zinc oxide? |
| 11 |
How many grams of 4 % hydrocortisone cream be mixed with 740 g of 0.75 % hydrocortisone cream to make a 1.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 3.25 L of 1: 2700 w/v solution to make a 1: 9300 w/v solution? |
| 13 |
How many grams of a 3.00 % 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
12 % 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 860 ml of 60 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 100 ml of water, 900 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 1.56 should be mixed with 6500 mL of a syrup having a specific gravity of 1.19 to obtain a product having a specific gravity of 1.42? |
Answers
The Answer to question 1 is: 4070.00 ml
The Answer to question 2 is: 6.47 % v/v
The Answer to question 3 is: 1 : 1683
The Answer to question 4 is: 0.35 %
The Answer to question 5 is: 63.57 ml
The Answer to question 6 is: 324.00 mg
The Answer to question 7 is: 47 % v/v
The Answer to question 8 is: 8.33 % w/v
The Answer to question 9 is: 2523.33 ml of 9 % , 12616.67 ml of 3 %
The Answer to question 10 is: 5 : 12
The Answer to question 11 is: 222.00 grams
The Answer to question 12 is: 7944.40 ml
The Answer to question 13 is: 5296.67 grams
The Answer to question 14 is: 39.06 ml
The Answer to question 15 is: 501.70 ml
The Answer to question 16 is: 1.01
The Answer to question 17 is: 10678.57 ml