Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 250 ml of a 56 % (w/v) solution to prepare 1 % w/v solution? |
| 2 | If 945 ml of a 30 % v/v solution is diluted to 2800 ml , what is the percent strength of the diluted solution? |
| 3 | If 985 ml of a 1 : 294 (w/v) solution is diluted to 2200 ml, what is the ratio strength of the new solution? |
| 4 | If 24 ml of a 0.70 % nasal spray was diluted with 28 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 14 % elixir can be prepared from 35 ml of a 63 % elixir? |
| 6 | If a cough syrup contains 24 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 7 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 350 ml of 40 % alcohol, 225 ml of 55 % alcohol, and 380 ml of 5 % alcohol? |
| 8 | A pharmacist combines 3 pints of a 5 % w/v povidone-iodine solution with 1 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 2 % and a 10 % solution do you need to prepare 3 gallon of 5 % solution? |
| 10 |
What proportion of 10 % zinc oxide and 55 % zinc oxide do you need to make 15 % zinc oxide? |
| 11 |
How many grams of 5 % hydrocortisone cream be mixed with 340 g of 0.25 % hydrocortisone cream to make a 2.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 2.25 L of 1: 2400 w/v solution to make a 1: 9100 w/v solution? |
| 13 |
How many grams of a 7.50 % 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
10 % 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 100 ml of 34 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 100 ml of water, 850 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 1.64 should be mixed with 2000 mL of a syrup having a specific gravity of 1.25 to obtain a product having a specific gravity of 1.29? |
Answers
The Answer to question 1 is: 13750.00 ml
The Answer to question 2 is: 10.13 % v/v
The Answer to question 3 is: 1 : 657
The Answer to question 4 is: 0.32 %
The Answer to question 5 is: 157.50 ml
The Answer to question 6 is: 132.00 mg
The Answer to question 7 is: 30 % v/v
The Answer to question 8 is: 7.00 % w/v
The Answer to question 9 is: 4258.13 ml of 10 % , 7096.88 ml of 2 %
The Answer to question 10 is: 8 : 1
The Answer to question 11 is: 198.33 grams
The Answer to question 12 is: 6281.30 ml
The Answer to question 13 is: 908.00 grams
The Answer to question 14 is: 29.33 ml
The Answer to question 15 is: 33.06 ml
The Answer to question 16 is: 1.01
The Answer to question 17 is: 228.57 ml