Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 220 ml of a 34 % (w/v) solution to prepare 6 % w/v solution? |
| 2 | If 475 ml of a 25 % v/v solution is diluted to 1700 ml , what is the percent strength of the diluted solution? |
| 3 | If 935 ml of a 1 : 272 (w/v) solution is diluted to 2300 ml, what is the ratio strength of the new solution? |
| 4 | If 35 ml of a 0.90 % nasal spray was diluted with 22 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 9 % elixir can be prepared from 30 ml of a 63 % elixir? |
| 6 | If a cough syrup contains 15 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 250 ml of 45 % alcohol, 175 ml of 75 % alcohol, and 130 ml of 5 % alcohol? |
| 8 | A pharmacist combines 7 pints of a 5 % w/v povidone-iodine solution with 4 quarts of 10 % w/v povidone-iodine solution. What is the strength of the resulting solution? |
| 9 |
How many milliliters of 1 % and a 10 % solution do you need to prepare 1 gallon of 9 % solution? |
| 10 |
What proportion of 15 % zinc oxide and 40 % zinc oxide do you need to make 25 % zinc oxide? |
| 11 |
How many grams of 2 % hydrocortisone cream be mixed with 660 g of 0.1 % hydrocortisone cream to make a 1.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 4.75 L of 1: 3300 w/v solution to make a 1: 5500 w/v solution? |
| 13 |
How many grams of a 8.50 % w/w benzocaine ointment can be prepared by diluting 1 lb of a 30 % w/w benzocaine ointment with white petrolatum? |
| 14 |
How many milliliters of a
18 % 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 90 ml of 30 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 400 ml of water, 800 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 1.60 should be mixed with 4500 mL of a syrup having a specific gravity of 1.18 to obtain a product having a specific gravity of 1.55? |
Answers
The Answer to question 1 is: 1026.67 ml
The Answer to question 2 is: 6.99 % v/v
The Answer to question 3 is: 1 : 669
The Answer to question 4 is: 0.55 %
The Answer to question 5 is: 210.00 ml
The Answer to question 6 is: 420.00 mg
The Answer to question 7 is: 45 % v/v
The Answer to question 8 is: 7.67 % w/v
The Answer to question 9 is: 3364.44 ml of 10 % , 420.56 ml of 1 %
The Answer to question 10 is: 3 : 2
The Answer to question 11 is: 594.00 grams
The Answer to question 12 is: 3166.70 ml
The Answer to question 13 is: 1602.35 grams
The Answer to question 14 is: 46.30 ml
The Answer to question 15 is: 26.25 ml
The Answer to question 16 is: 0.99
The Answer to question 17 is: 33300.00 ml