Alligation
Alligation is used to calculate how to mix two solutions of different concentrations to get a solution of desired
strength.
1) Mix 12% and 3% potassium chloride solutions to prepare 250 mL of 7% solution. How much of each do you
need?
2) Find the ratio to mix 25% and 7% calcium gluconate solutions to obtain a 15% solution.
3) Calculate the volumes of 8% and 2% sodium bicarbonate solutions needed to prepare 300 mL of 5% sodium
bicarbonate.
4) You have 20% and 5% dextrose solutions. How much of each is required to prepare 1 litre of 10% dextrose?
5) You have 25% and 4% potassium chloride solutions. Calculate the volumes needed to prepare 350 mL of a 10%
solution.
6) How do you mix 18% and 6% saline solutions to obtain 400 mL of 12% saline?
7) How much 15% and 5% glucose solutions should be mixed to produce 1.2 litres of 9% glucose?
8) A pharmacist needs to prepare 500 mL of 12% sodium chloride by mixing 18% and 6% sodium chloride solutions.
Calculate the required volumes.
9) Calculate the ratio to mix 40% and 10% calcium gluconate to obtain a 22% solution.
10) Prepare 750 mL of 7.5% potassium iodide solution by mixing 20% and 5% solutions. Find the volume of each.
11) A 30% and a 7% magnesium sulfate solution are mixed to form 1 litre of 12% solution. Calculate the volumes
needed.
12) Calculate the ratio and volume needed of 10% and 1% hydrocortisone cream to make 200 g of 5% cream.
13) How much of 28% and 8% calcium chloride solutions are mixed to prepare 600 mL of 18% calcium chloride?
14) A solution of 22% and 4% silver nitrate are mixed to make 300 mL of 7% solution. Calculate volumes required.
15) Mix 16% and 2% lidocaine solutions to prepare 250 mL of 5% lidocaine. Calculate the volumes.
16) A pharmacist mixes 12% and 0.5% potassium permanganate to make 400 mL of 2% solution. Find volumes of
each.
17) Prepare 500 mL of 15% urea solution by mixing 25% and 5% solutions. Calculate volumes needed.
18) How much 35% and 12% benzoyl peroxide solutions are needed to prepare 100 mL of 18% solution?
19) Calculate the volumes of 50% and 15% ethanol needed to prepare 2 litres of 30% ethanol solution.
Alligation is used to calculate how to mix two solutions of different concentrations to get a solution of desired
strength.
1) Mix 12% and 3% potassium chloride solutions to prepare 250 mL of 7% solution. How much of each do you
need?
2) Find the ratio to mix 25% and 7% calcium gluconate solutions to obtain a 15% solution.
3) Calculate the volumes of 8% and 2% sodium bicarbonate solutions needed to prepare 300 mL of 5% sodium
bicarbonate.
4) You have 20% and 5% dextrose solutions. How much of each is required to prepare 1 litre of 10% dextrose?
5) You have 25% and 4% potassium chloride solutions. Calculate the volumes needed to prepare 350 mL of a 10%
solution.
6) How do you mix 18% and 6% saline solutions to obtain 400 mL of 12% saline?
7) How much 15% and 5% glucose solutions should be mixed to produce 1.2 litres of 9% glucose?
8) A pharmacist needs to prepare 500 mL of 12% sodium chloride by mixing 18% and 6% sodium chloride solutions.
Calculate the required volumes.
9) Calculate the ratio to mix 40% and 10% calcium gluconate to obtain a 22% solution.
10) Prepare 750 mL of 7.5% potassium iodide solution by mixing 20% and 5% solutions. Find the volume of each.
11) A 30% and a 7% magnesium sulfate solution are mixed to form 1 litre of 12% solution. Calculate the volumes
needed.
12) Calculate the ratio and volume needed of 10% and 1% hydrocortisone cream to make 200 g of 5% cream.
13) How much of 28% and 8% calcium chloride solutions are mixed to prepare 600 mL of 18% calcium chloride?
14) A solution of 22% and 4% silver nitrate are mixed to make 300 mL of 7% solution. Calculate volumes required.
15) Mix 16% and 2% lidocaine solutions to prepare 250 mL of 5% lidocaine. Calculate the volumes.
16) A pharmacist mixes 12% and 0.5% potassium permanganate to make 400 mL of 2% solution. Find volumes of
each.
17) Prepare 500 mL of 15% urea solution by mixing 25% and 5% solutions. Calculate volumes needed.
18) How much 35% and 12% benzoyl peroxide solutions are needed to prepare 100 mL of 18% solution?
19) Calculate the volumes of 50% and 15% ethanol needed to prepare 2 litres of 30% ethanol solution.
