Practice problems

# Question
1 What is the density of 34 ml of a liquid that weighs 98 g ?
2 What is the weight in grams of 78 ml liquid, with a specific gravity of 3.56?
3 If a drug has specific gravity of 2.20. How many ml of drug do you need to get 10 g of drug?
4 What is the specific gravity of a 485 ml of liquid that weighs 423 g?
5 How many mg of a drug will be there in 5 ml of 0.25 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 210 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 3030 ml of 80 % solution?
8 Calculate the % w/v of 2 w/w % NaCl solution having a specific gravity of 1.01.
9 Calculate the % w/w of a solution prepared by dissolving 85 g of a drug in 1400 ml of water?
10 A pharmacist dispenses 50 ml of 8 % 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 : 899 as a percent strength.
12 Express 0.50 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 20 ml of a 1: 385 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 2600
Hydrophilic ointment ad 75 g
Sig. apply
15 Express 30 g in 400 ml as mg/ml.
16 Express 71 % w/v as mg/ml.
17 Express 1: 2000 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 9 ml of tap water contains 3 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 2.88 g/ml

The Answer to question 2 is: 277.68 g

The Answer to question 3 is: 4.55 ml

The Answer to question 4 is: 0.87

The Answer to question 5 is: 12.50 mg

The Answer to question 6 is: 147.00 ml

The Answer to question 7 is: 2424.00 g

The Answer to question 8 is: 2.02 % w/v

The Answer to question 9 is: 5.72 % w/w

The Answer to question 10 is: 400 mg

The Answer to question 11 is: 0.11 %

The Answer to question 12 is: 1 : 200

The Answer to question 13 is: 51.95 mg

The Answer to question 14 is: 28.85 mg

The Answer to question 15 is: 75.00 mg/ml

The Answer to question 16 is: 710.00 mg/ml

The Answer to question 17 is: 0.50 mg/ml

The Answer to question 18 is: 3.33 ppm