Chemistry 2202 Unit 1 Test 3Page 1 of 8
Chemistry 2202 Unit 1 Test 3
2006 – 07
Directions:Write all responses in the spaces provided. Please use a pen. Submit ALL pages of this test (including any pages containing workings/outlines) to your supervising teacher upon completion.
Part 1 – Multiple Choice:Circle answers on the answer form on page 4. (1 point each)
1.Percent composition analysisof a gasoline sample gave these results.
Hydrocarbons / hexane / heptane / octane / nonane / other hydrocarbonsPercent Composition / 13.26% / 25.78% / 32.90% / 16.59% / 11.47
Which hydrocarbon is the solvent?
A.C6H14
B.C7H16
C.C8H18
D.C9H20
2.Which dissociates in water to form an electrolytic solution?
A.CaBr2(s)
B.Cl2O(g)
C.HCl(g)
D.I2(s)
3.Which has high solubility in water?
A.Ca3(PO4)2
B.CaSO4
C.K2CrO4
D.Zn(OH)2
4.Which is the dissociation equation for barium cyanide?
A.
B.
C.
D.
5.What is the molar concentrationof a 500. mL solution that contains 0.30 mol of sodium chloride?
A.0.00060 mol/L
B.0.15 mol/L
C.0.60 mol/L
D.150 mol/L
6.Aqueous sodium chloride is left in an open beaker for seven days. The concentration of the solution was measured each day. The results were graphed below.
Which interpretation of the graph is correct?
A.After the third day, the solution became unsaturated.
B.After the third day, the solution became saturated.
C.On the first day, the solution was saturated.
D.On the first day, the solution was supersaturated.
7.A solution of copper(II) sulfate contains a single, undissolved, blue copper(II) sulfate crystal at 25°C. Stirring the solution does not cause a change in the mass of the crystal. Which interpretation is correct?
A.a dynamic equilibrium exists
B.a precipitate has formed
C.the solution is dilute
D.the solution is supersaturated
8.How many moles of solute are required to make 300. mL of 0.600 M zinc nitrate solution?
A.0.180 mol
B.0.500 mol
C.2.00 mol
D.180 mol
9.What volume of 2.00 mol/L HCl(aq) solution contains 0.650 mol?
A. 0.130 L
B. 0.325 L
C. 1.30L
D. 3.08 L
10.What is the mass of solute in 100. mL of a 1.023 10-3 M Na3PO4(aq) (molar mass = 163.94 g/mol)?
A.1.00 x 10-4 g
B.0.0168 g
C.0.168 g
D.16.8 g
11.A solution is made by adding 10.0 mL of 6.00 mol/L HCl to 90.0 mL of water. What can be said about the new solution?
A.Its concentration is less than 6.0 mol/L.
B.Its concentration is greater than 6.0 mol/L.
C.It contains fewer moles of solute.
D.It contains more moles of solute.
12.A hair stylist needs to dilute some hydrogen peroxide to bleach a client’s hair. What volume of 1.8 mol/L H2O2(aq) does she need to use to make 75.0 mL of a 0.55 mol/Lsolution?
A.0.013 mL
B.0.73 mL
C.23 mL
D.54 mL
13.What are the ion concentrations in a 0.24 M solution of Na3PO4?
[Na+] / [PO43-]A. / 0.24 M / 0.24 M
B. / 0.24 M / 0.72 M
C. / 0.080 M / 0.24 M
D. / 0.72 M / 0.24 M
14.What concentration of Al(NO3)3(aq) will have a NO3-(aq) ion concentration of 1.8 10-3 mol/L?
A.1.8 10-3 mol/L
B.5.4 10-3 mol/L
C.6.0 10-4 mol/L
D.9.0 10-4 mol/L
15.Which correctlyidentifies the reactants in a precipitation reaction and the identity of the precipitate?
Reactants / PrecipitateA. / BeI2(aq) + Sr(NO3)2(g) / Be(NO3)2(s)
B. / LiCl(aq) + Al(CH3COO)3(aq) / LiCH3COO(s)
C. / Na2CO3(aq) + Ba(NO3)2(aq) / NaNO3(s)
D. / ZnCl2(g) + Ba(OH)2(aq) / Zn(OH)2(s)
Chemistry 2202 Unit 1 Test 3Page 1 of 8
Chemistry 2202 Unit 1 Test 3Page 1 of 8
Name: ______Site ______
Chemistry 2202 – Unit 1 Test 3
Answer Forms
Part 1: For each item, circle the letter corresponding to your choice.
1.ABCD 6.ABCD11.ABCD
2.ABCD 7.ABCD12.ABCD
3.ABCD 8.ABCD13.ABCD
4.ABCD 9.ABCD14.ABCD
5.ABCD10.ABCD15.ABCD
Part 2:Write your responses in the spaces provided. Showall workings and be neat!
(2)16.a)Biff and Molly are hungry. They decide to eat a can of soup. A 284 mL can of Chicken Noodle Soup contains 4.45 g of salt, NaCl.Calculate the molar concentration of NaCl in the soup.
(2)b)i)Biff and Mollyare thirsty and their electrolytes are depleted. Biff mixes 250 mL of 0.50 mol/L orange coloured sports drink concentrate with 750 mL of water. Calculate the molar concentration of the diluted solution.
(1)ii)Molly sees two bottles of sports drink on the picnic blanket. List two observations she can make to distinguish between the concentrated and diluted solutions in (i) above.
The diluted solution will have a lower color intensity.
The flavor of the diluted solution will be less intense or more “watery”.
(3)17.Biff and Mollyreacted50.0 mL of Al2(SO4)3(aq) with excess Ca(NO3)2(aq)producing 2.53 g of precipitate.
Calculate the molar concentration of the Al2(SO4)3(aq) solution.
(2) 18. Biff made0.100 M solutions of AgClO3(aq) and Ca(NO3)2(aq), but he forgot to label them. So Molly suggested that he add either NaCl(aq) or Na2SO4(aq) to samples of each solution.
Explain which solution will help him identify the AgClO3 solution.
The formation of a precipitate is a useful way to identify unknown solutions.
Use the solubility table to see which solutions give precipitates with NaCl(aq) and Na2SO4(aq):
NaCl(aq): Na+ is a group IA ion and forms high solubility (aq) compounds. Check Cl- with Ag+ and Ca2+ for low solubility (precipitate) products.
NaCl will form a precipitate with AgClO3 but not Ca(NO3)2. It can be used to distinguish between the two solutions.
Na2SO4(aq): Na+ is a group IA ion and forms high solubility (aq) compounds. Check SO42- with Ag+ and Ca2+ for low solubility (precipitate) products.
Precipitates will form in both reactions, so Na2SO4 cannot be used to distinguish these solutions.
19.Lead ions can be removed from drinking water by adding table salt, NaCl(aq):
(2)a)Describe a procedure toisolate and purify the PbCl2 precipitate. Include a diagram of the apparatus used in the procedure.
Mass a dry piece of filter paper. Fold the paper and put in a funnel. Filter the reaction mixture, collecting the PbCl2(s) precipitate. Wash the precipitate to ensure all the soluble compounds have drained through to the filtrate.
Carefully lift the filter paper out of the funnel and spread it out to dry. Leave it for a day or so until it is dry, then mass the filter paper with the precipitate.
Subtract to determine the mass of precipitate formed.
(3)b)If 3.0 L of 0.0400 mol/L NaCl(aq)is added to 5.0 L of 0.01000 mol/L Pb(NO3)2(aq), would all of the lead ions be precipitated out of the Pb(NO3)2(aq) solution? Use calculations to justify your answer.
If all of the lead ions are precipitated out, Pb(NO3)2(aq) would be the limiting reactant, and NaCl would be the excess reactant.