Practice problems

# Question
1 What is the density of 82 ml of a liquid that weighs 150 g ?
2 What is the weight in grams of 419 ml liquid, with a specific gravity of 3.24?
3 If a drug has specific gravity of 3.00. How many ml of drug do you need to get 50 g of drug?
4 What is the specific gravity of a 20 ml of liquid that weighs 278 g?
5 How many mg of a drug will be there in 5 ml of 0.40 % w/v timolol ophthalmic solution?
6 What is the volume of isopropyl alcohol required to make 270 ml of rubbing alcohol (70% v/v isopropyl alcohol)
7 How many grams of dextrose are required to prepare 2480 ml of 54 % solution?
8 Calculate the % w/v of 14 w/w % NaCl solution having a specific gravity of 1.098.
9 Calculate the % w/w of a solution prepared by dissolving 20 g of a drug in 2900 ml of water?
10 A pharmacist dispenses 25 ml of 16 % 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 : 669 as a percent strength.
12 Express 0.10 % as a ratio strength.
13 Calculate the milligrams of drug required to prepare 95 ml of a 1: 145 antiseptic solution.
14 How many milligrams of hexachlorophene should be used in compounding the following prescription?

Hexachlorophene 1 : 500
Hydrophilic ointment ad 65 g
Sig. apply
15 Express 5 g in 450 ml as mg/ml.
16 Express 82 % w/v as mg/ml.
17 Express 1: 1900 (w/v) as mg/ml.
18 Calculate the concentration of copper in ppm if 66 ml of tap water contains 8 X 10 -5 parts of copper.

Answers

The Answer to question 1 is: 1.83 g/ml

The Answer to question 2 is: 1357.56 g

The Answer to question 3 is: 16.67 ml

The Answer to question 4 is: 13.90

The Answer to question 5 is: 20.00 mg

The Answer to question 6 is: 189.00 ml

The Answer to question 7 is: 1339.20 g

The Answer to question 8 is: 15.37 % w/v

The Answer to question 9 is: 0.68 % w/w

The Answer to question 10 is: 800 mg

The Answer to question 11 is: 0.15 %

The Answer to question 12 is: 1 : 1000

The Answer to question 13 is: 655.17 mg

The Answer to question 14 is: 130.00 mg

The Answer to question 15 is: 11.11 mg/ml

The Answer to question 16 is: 820.00 mg/ml

The Answer to question 17 is: 0.53 mg/ml

The Answer to question 18 is: 1.21 ppm