Practice problems

# Question
1 What is the density of 92 ml of a liquid that weighs 271 g ?
2 What is the weight in grams of 70 ml liquid, with a specific gravity of 3.70?
3 If a drug has specific gravity of 2.80. How many ml of drug do you need to get 10 g of drug?
4 What is the specific gravity of a 185 ml of liquid that weighs 303 g?
5 How many mg of a drug will be there in 25 ml of 0.40 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 780 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 2540 ml of 71 % solution?
8 Calculate the % w/v of 16 w/w % NaCl solution having a specific gravity of 1.11.
9 Calculate the % w/w of a solution prepared by dissolving 40 g of a drug in 1600 ml of water?
10 A pharmacist dispenses 75 ml of 7 % w/v ibuprofen suspension, which is to be taken as 2 teaspoonful’s per day. How many milligrams of ibuprofen are contained per teaspoonful?
11 Express 1 : 198 as a percent strength.
12 Express 0.60 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 80 ml of a 1: 165 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 2400
Hydrophilic ointment ad 55 g
Sig. apply
15 Express 33 g in 400 ml as mg/ml.
16 Express 13 % w/v as mg/ml.
17 Express 1: 4200 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 88 ml of tap water contains 2 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 2.95 g/ml

The Answer to question 2 is: 259.00 g

The Answer to question 3 is: 3.57 ml

The Answer to question 4 is: 1.64

The Answer to question 5 is: 100.00 mg

The Answer to question 6 is: 546.00 ml

The Answer to question 7 is: 1803.40 g

The Answer to question 8 is: 17.76 % w/v

The Answer to question 9 is: 2.44 % w/w

The Answer to question 10 is: 350 mg

The Answer to question 11 is: 0.51 %

The Answer to question 12 is: 1 : 166

The Answer to question 13 is: 484.85 mg

The Answer to question 14 is: 22.92 mg

The Answer to question 15 is: 82.50 mg/ml

The Answer to question 16 is: 130.00 mg/ml

The Answer to question 17 is: 0.24 mg/ml

The Answer to question 18 is: 0.23 ppm