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Unit Test Dec 2010 (1)

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SCH3U: Solutions and Solubility Unit Test
1. A sugar solution is found to be 14 % w/v.
a) What is the molarity of this solution if the sugar is glucose (C6H12O6)? (2 TI marks)
b) How would you prepare 250 mL of a sugar solution that is 1/10th of its original
concentration?
(3 TI marks)
2. Calculate the mass of Ag2CrO4 that forms when 1.5 g of silver nitrate reacts with 20.0
mL of 0.400 mol/L sodium chromate. 2AgNO3 (s) + Na2CrO4 (aq) → Ag2CrO4(s) +
2NaNO3 (aq) (4 TI marks)
3. An analysis showed that 12.1 mL of 0.150 mol/L NaOH (aq) is needed for the titration
of 20.0 mL of sulfuric acid (H2SO4 (aq)). Determine the concentration of this acid. (3
marks)
4. Using a T-chart compare acids and bases for the following:
a) pH range
b) Arrhenius’s definition
c) Bronsted-Lowry definition
d) Electrical conductivity
e) Reaction to phenolphthalein
f) Two specific examples of each
5. How would you prepare 200 mL of 0.500 mol/L NaCl solution starting with solid
NaCl? (2 marks)
6. Using a flow chart method show how you would separate the cations from the
following mixture by precipitating each ion out of the solution: Ag+, Ba2+, Zn2+.
Remember to identify the state of each compound as either solid (s) or aqueous (aq). (3
marks)
7. Read the following ISSUE first, then respond to the questions below. Keep your
responses concise. You may use point form, or a table to organize some of your answers.
ISSUE: In developing countries, thousands of people, many of them children, die every
year from drinking contaminated water. Many of these countries cannot afford to build
water treatment plants. In North America, where safe water is generally available, we
spend millions of dollars on bottled water, draining sources of fresh water and
challenging waste-disposal systems.
QUESTIONS:
i) Discuss what do you see as the underlying economic, social and environmental issues?
(5 marks)
ii) How do you feel about the issue? (2 marks)
iii) Can you suggest or propose an action plan to address the issue? (3 marks)
8.
i. At what temperature are the solubilities of KCl (s) and KNO3(s) equal? (1 mark)
ii. How many grams of NH4Cl (s) should be dissolved in 100 g of water at 500C to make
a saturated solution? (1 mark)
iii. Explain how do the solubilities of solids and of gases vary with increasing
temperature? (2 marks)
iv. Which salt has the lowest solubility at 300C? ____________________ (1 mark)
9. Write the balanced chemical equation and the net ionic equation for the reaction of
aqueous lead (II) nitrate and aqueous sodium sulfate. (3 TI marks)
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