Practice problems

# Question
1 What is the density of 153 ml of a liquid that weighs 112 g ?
2 What is the weight in grams of 194 ml liquid, with a specific gravity of 1.00?
3 If a drug has specific gravity of 2.80. How many ml of drug do you need to get 55 g of drug?
4 What is the specific gravity of a 20 ml of liquid that weighs 8 g?
5 How many mg of a drug will be there in 15 ml of 0.45 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 280 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 870 ml of 86 % solution?
8 Calculate the % w/v of 10 w/w % NaCl solution having a specific gravity of 1.068.
9 Calculate the % w/w of a solution prepared by dissolving 10 g of a drug in 150 ml of water?
10 A pharmacist dispenses 90 ml of 14 % 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 : 582 as a percent strength.
12 Express 5.50 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 50 ml of a 1: 395 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 2300
Hydrophilic ointment ad 90 g
Sig. apply
15 Express 40 g in 850 ml as mg/ml.
16 Express 10 % w/v as mg/ml.
17 Express 1: 4900 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 49 ml of tap water contains 2 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 0.73 g/ml

The Answer to question 2 is: 194.00 g

The Answer to question 3 is: 19.64 ml

The Answer to question 4 is: 0.40

The Answer to question 5 is: 67.50 mg

The Answer to question 6 is: 196.00 ml

The Answer to question 7 is: 748.20 g

The Answer to question 8 is: 10.68 % w/v

The Answer to question 9 is: 6.25 % w/w

The Answer to question 10 is: 700 mg

The Answer to question 11 is: 0.17 %

The Answer to question 12 is: 1 : 18

The Answer to question 13 is: 126.58 mg

The Answer to question 14 is: 39.13 mg

The Answer to question 15 is: 47.06 mg/ml

The Answer to question 16 is: 100.00 mg/ml

The Answer to question 17 is: 0.20 mg/ml

The Answer to question 18 is: 0.41 ppm