Practice problems

# Question
1 What is the density of 30 ml of a liquid that weighs 28 g ?
2 What is the weight in grams of 395 ml liquid, with a specific gravity of 1.44?
3 If a drug has specific gravity of 1.60. How many ml of drug do you need to get 45 g of drug?
4 What is the specific gravity of a 15 ml of liquid that weighs 27 g?
5 How many mg of a drug will be there in 20 ml of 0.35 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 110 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 60 ml of 86 % solution?
8 Calculate the % w/v of 24 w/w % NaCl solution having a specific gravity of 1.18.
9 Calculate the % w/w of a solution prepared by dissolving 75 g of a drug in 3800 ml of water?
10 A pharmacist dispenses 95 ml of 3 % 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 : 490 as a percent strength.
12 Express 0.40 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 25 ml of a 1: 440 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 2400
Hydrophilic ointment ad 60 g
Sig. apply
15 Express 63 g in 750 ml as mg/ml.
16 Express 34 % w/v as mg/ml.
17 Express 1: 400 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 98 ml of tap water contains 8 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 0.93 g/ml

The Answer to question 2 is: 568.80 g

The Answer to question 3 is: 28.13 ml

The Answer to question 4 is: 1.80

The Answer to question 5 is: 70.00 mg

The Answer to question 6 is: 77.00 ml

The Answer to question 7 is: 51.60 g

The Answer to question 8 is: 28.32 % w/v

The Answer to question 9 is: 1.94 % w/w

The Answer to question 10 is: 150 mg

The Answer to question 11 is: 0.20 %

The Answer to question 12 is: 1 : 250

The Answer to question 13 is: 56.82 mg

The Answer to question 14 is: 25.00 mg

The Answer to question 15 is: 84.00 mg/ml

The Answer to question 16 is: 340.00 mg/ml

The Answer to question 17 is: 2.50 mg/ml

The Answer to question 18 is: 0.82 ppm