Practice problems
| # | Question |
|---|---|
| 1 | How many milliliters of water should be added to 140 ml of a 34 % (w/v) solution to prepare 1 % w/v solution? |
| 2 | If 405 ml of a 85 % v/v solution is diluted to 500 ml , what is the percent strength of the diluted solution? |
| 3 | If 595 ml of a 1 : 292 (w/v) solution is diluted to 2300 ml, what is the ratio strength of the new solution? |
| 4 | If 35 ml of a 0.50 % nasal spray was diluted with 2 ml of normal saline solution, what would be the final drug concentration? |
| 5 | How many milliliters of a 12 % elixir can be prepared from 80 ml of a 48 % elixir? |
| 6 | If a cough syrup contains 32 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 9 mg/ml? |
| 7 | What is the percentage strength (v/v) of an alcohol mixture that has a mix of 350 ml of 35 % alcohol, 100 ml of 50 % alcohol, and 270 ml of 20 % alcohol? |
| 8 | A pharmacist combines 2 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 5 % and a 16 % solution do you need to prepare 2 gallon of 7 % solution? |
| 10 |
What proportion of 5 % zinc oxide and 70 % zinc oxide do you need to make 30 % zinc oxide? |
| 11 |
How many grams of 2 % hydrocortisone cream be mixed with 320 g of 0.25 % hydrocortisone cream to make a 1.00 % hydrocortisone cream? |
| 12 |
How many milliliters of water should be added to 3.25 L of 1: 1800 w/v solution to make a 1: 8200 w/v solution? |
| 13 |
How many grams of a 2.50 % 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
26 % 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 260 ml of 48 % (w/v) lactic acid solution? |
| 16 |
What is the specific gravity of a mixture containing 600 ml of water, 1350 ml of glycerin having a specific gravity of 1.25, and 1300 ml of alcohol having a specific gravity of 0.81? |
| 17 |
How many milliliters of a syrup having a specific gravity of 1.47 should be mixed with 3000 mL of a syrup having a specific gravity of 1.29 to obtain a product having a specific gravity of 1.38? |
Answers
The Answer to question 1 is: 4620.00 ml
The Answer to question 2 is: 68.85 % v/v
The Answer to question 3 is: 1 : 1129
The Answer to question 4 is: 0.47 %
The Answer to question 5 is: 320.00 ml
The Answer to question 6 is: 156.00 mg
The Answer to question 7 is: 31 % v/v
The Answer to question 8 is: 9.55 % w/v
The Answer to question 9 is: 1376.36 ml of 16 % , 6193.64 ml of 5 %
The Answer to question 10 is: 8 : 5
The Answer to question 11 is: 240.00 grams
The Answer to question 12 is: 11555.60 ml
The Answer to question 13 is: 5448.00 grams
The Answer to question 14 is: 12.06 ml
The Answer to question 15 is: 121.34 ml
The Answer to question 16 is: 1.03
The Answer to question 17 is: 3000.00 ml