Practice problems

# Question
1 What is the density of 132 ml of a liquid that weighs 183 g ?
2 What is the weight in grams of 43 ml liquid, with a specific gravity of 1.34?
3 If a drug has specific gravity of 0.40. How many ml of drug do you need to get 25 g of drug?
4 What is the specific gravity of a 70 ml of liquid that weighs 57 g?
5 How many mg of a drug will be there in 5 ml of 0.15 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 720 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 320 ml of 38 % solution?
8 Calculate the % w/v of 22 w/w % NaCl solution having a specific gravity of 1.16.
9 Calculate the % w/w of a solution prepared by dissolving 15 g of a drug in 1500 ml of water?
10 A pharmacist dispenses 70 ml of 17 % 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 : 803 as a percent strength.
12 Express 0.60 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 20 ml of a 1: 170 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 3200
Hydrophilic ointment ad 10 g
Sig. apply
15 Express 20 g in 750 ml as mg/ml.
16 Express 3 % w/v as mg/ml.
17 Express 1: 200 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 91 ml of tap water contains 7 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 1.39 g/ml

The Answer to question 2 is: 57.62 g

The Answer to question 3 is: 62.50 ml

The Answer to question 4 is: 0.81

The Answer to question 5 is: 7.50 mg

The Answer to question 6 is: 504.00 ml

The Answer to question 7 is: 121.60 g

The Answer to question 8 is: 25.52 % w/v

The Answer to question 9 is: 0.99 % w/w

The Answer to question 10 is: 850 mg

The Answer to question 11 is: 0.12 %

The Answer to question 12 is: 1 : 166

The Answer to question 13 is: 117.65 mg

The Answer to question 14 is: 3.13 mg

The Answer to question 15 is: 26.67 mg/ml

The Answer to question 16 is: 30.00 mg/ml

The Answer to question 17 is: 5.00 mg/ml

The Answer to question 18 is: 0.77 ppm