Concentration and Dilution Assignment

10/24/2008

Science 20 Unit A – Chemistry

Concentration and Dilution Assignment

Show all work to receive full marks! This includes units, starting equations or the proper unit canceling method! Also, don’t forget about your friend Sig Digs!!!

Percent Volume

1. At a local salon called Curl up and Dye a woman has mysteriously become ill. Earlier that day she was exposed to a hydrogen peroxide solution containing 3% hydrogen peroxide. If she received 7mL of solution how much of the solution was hydrogen peroxide?(2 marks)

2. At a mechanical shop grease removing soap is made from a concentrated liquid. A new apprentice wants to mix the solution for 8%.If he uses 24mL of soap concentrate, what is the volume of the final solution of the soap mixture? (2 marks)

3. A new infectious disease has been discovered called LD Fever. This disease can only be cured by a special antibiotic called Donarus; however, this antibiotic is lethal if given at a dose of 6%.

a)If the patient needs a dose of 4% to be cured and the final solution has a volume of 2mL how much Donarus needs to be used in the dose? (2 marks)

b)How much of the drug will make the 2 mL dose fatal? (2 marks)

c)If you catch this disease and the doctor prescribes 3mL of solution containing 0.14mL of Donarus what is the final % volume of the solution? And, are you dead, or do you just need a new doctor? (3 marks)

Parts Per Million

4. Acid rain may have 335 ppm of dissolved carbon dioxide. What mass of carbon dioxide is present in 1.00 L of acid rain? (2 marks)

5. In the Alaskan oil pipelines regular soil samples are taken to ensure that oil is not seeping from the pipeline. In a 100g sample there was found to be 2.6 x10-3 g of oil in the sample. How many parts per million of oil are present in the soil? (2 marks)

6. A water sample is taken near a uranium mine. The maximum acceptable level of uranium in water is 0.02ppm. If 1.9 x10 -6 g of uranium is found in 50g of water has this water been contaminated? (3 marks)

Amount Concentration

7. Copper (II) sulphate (CuSO4(aq))is used in copper electroplating cells. What is the molar concentration of an electroplating solution in which 1.50 mol of copper (II) sulfate is dissolved in water to make 2.00 L of solution? (2 marks)

8. When 11.0 g of purevinegar (chemical name: acetic acid, CH3COOH(aq)) is dissolved in water to make 250 mL of solution, what is the molar concentration of the solution?(3 marks)

9. Sodium bicarbonate is used medicinally to counteract excess stomach acidity. How many moles of solid sodium bicarbonate would be needed to make 100 mL of 0.660 mol/L solution for use as an antacid?(2 marks)

10. A rust stain remover may be prepared by dissolving potassium persulphate (K2SO5) in water. How many grams of this compound are there in 500 mL of a 0.242 mol/L solution suitable for removing rust stains?(2 marks)

Bonus Question: Answer Only ONE!!!

Fair Bonus Question: What is the concentration of common eating vinegar?

Unfair Bonus Question: What is your favorite type of vinegar to eat and why?

LD Industries