Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 170 ml of a 66 % (w/v) solution to prepare 10 % w/v solution? |
| 2 | If 700 ml of a 40 % v/v solution is diluted to 2900 ml , what is the percent strength of the diluted solution? |
| 3 | If 760 ml of a 1 : 190 (w/v) solution is diluted to 1900 ml, what is the ratio strength of the new solution? |
| 4 | If 13 ml of a 0.50 % nasal spray was diluted with 26 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 8 % elixir can be prepared from 35 ml of a 61 % elixir? |
| 6 | If a cough syrup contains 47 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 35 % alcohol, 125 ml of 65 % alcohol, and 160 ml of 5 % alcohol? |
| 8 | A pharmacist combines 2 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 4 % and a 10 % solution do you need to prepare 2 gallon of 9 % solution? |
| 10 |
What proportion of 15 % zinc oxide and 35 % zinc oxide do you need to make 25 % zinc oxide? |
| 11 |
How many grams of 5 % hydrocortisone cream be mixed with 700 g of 0.25 % hydrocortisone cream to make a 2.50 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 2.50 L of 1: 700 w/v solution to make a 1: 8900 w/v solution? |
| 13 |
How many grams of a 5.00 % 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
25 % 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 450 ml of 30 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 900 ml of water, 1350 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 1.38 should be mixed with 2000 mL of a syrup having a specific gravity of 1.18 to obtain a product having a specific gravity of 1.36? |
Answers
The Answer to question 1 is: 952.00 ml
The Answer to question 2 is: 9.66 % v/v
The Answer to question 3 is: 1 : 475
The Answer to question 4 is: 0.17 %
The Answer to question 5 is: 266.88 ml
The Answer to question 6 is: 36.00 mg
The Answer to question 7 is: 33 % v/v
The Answer to question 8 is: 8.75 % w/v
The Answer to question 9 is: 6308.33 ml of 10 % , 1261.67 ml of 4 %
The Answer to question 10 is: 1 : 1
The Answer to question 11 is: 630.00 grams
The Answer to question 12 is: 29285.70 ml
The Answer to question 13 is: 3178.00 grams
The Answer to question 14 is: 18.82 ml
The Answer to question 15 is: 131.26 ml
The Answer to question 16 is: 1.05
The Answer to question 17 is: 18000.00 ml