Form Code A
CHEM 1025 Exam # 2
18 Feb. 2010
Instructions: On your scantron sheet enter your name, UF ID number, and Form Code (start with the first space and leave
the last space blank). This exam consists of 25 multiple choice questions each worth 8.0 points for a total maximum of
200 pts. Keep your exam sheet (mark your answers on it and on the scantron sheet). Turn in only the scantron. Any
bubbling error will count as an incorrect response, including wrong form code and answers.
1. Iron is mined from the earth as iron ore. Hematite, Fe2O3, is one of the common ores. Calculate the mass percent
composition of iron.
(1) 27.99%
(2) 34.97%
(3) 69.9%
(4) 1.43%
(5) 55.98%
2. Silver Chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride required to
plate 155 mg of pure silver.
(1) 0.206 g
(2) 0.117 g
(3) 206 g
(4) 0.383 g
(5) 117 g
3. Butane (C4H10) is used as a liquid fuel in lighters. How many grams of carbon are present within a lighter containing
7.25 mL of butane? (The density of liquid butane is 0.601 g/mL).
(1) 2.25 g
(2) 9.97 g
(3) 12.2 g
(4) 3.60 g
(5) 2.50 g
4. Calculate the empirical formula for methyl butyrate (component of apple taste and smell) based on its elemental mass
percent composition: C 58.80%, H 9.87%, and O 31.33%.
(1) C2H10O2
(2) C3H5O
(3) C2H5O
(4) C3H10O2
(5) C5H10O2
5. Calculate the molecular formula for nicotine based on its elemental mass percent composition (C 74.03%, H 8.70%,
and N 17.27%) and its molar mass (162.26 g/mol).
(1) C10H14N2
(2) C15H21N3
(3) C4H6N
(4) C5H7N
(5) C8H12N2
6. Tartaric acid is the white, powdery substance that coats sour candies such as Sour Patch Kids. Combustion analysis of
a 12.01 g sample of tartaric acid – which contains only carbon, hydrogen, and oxygen – produced 14.08 g CO2 and
4.32 g H2O. Find the empirical formula for tartaric acid.
(1) C2H2O
(2) CHO
(3) C8HO16
(4) C2H3O3
(5) CH2O2
7. Balance the following equation: HCl(aq) + O2(g) → H2O(l) + Cl2(g)
(1) 4HCl(aq) + O2(g) → 2H2O(l) + Cl2(g)
(2) 6HCl(aq) + O2(g) → 2H2O(l) + 3Cl2(g)
(3) 4HCl(aq) + O2(g) → 2H2O(l) + 2Cl2(g)
(4) 2HCl(aq) + O2(g) → H2O(l) + Cl2(g)
(5) 6HCl(aq) + O2(g) → 3H2O(l) + 3Cl2(g)
8. Magnesium oxide can be made by heating magnesium metal in the presence of the oxygen. The balanced equation for
the reaction is
2Mg(s) + O2(g) → 2MgO(s)
When 10.1 g of Mg is allowed to react with 10.5 g O2, 11.9 g MgO is collected. Determine the theoretical yield of
MgO for the reaction.
(1) 6.61 g
(2) 16.7 g
(3) 11.9 g
(4) 26.5 g
(5) 8.37 g
9. The following reaction is used to obtain iron from iron ore:
Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)
The reaction of 167 g Fe2O3 with 85.8 g CO produces 72.3 g Fe. Determine the percent yield assuming that CO is the
limiting reagent.
(1) 84.3%
(2) 28.2%
(3) 61.9%
(4) 21.1%
(5) 63.4%
10. Calculate the molarity of 15.2 mg KI in 102 mL of solution.
(1) 8.98 x 10-7 M
(2) 1.49 x 10-4 M
(3) 0.898 M
(4) 8.98 x 10-4 M
(5) 1.49 x 10-7 M
11. A chemist wants to make 5500 mL of a 0.300 M CaCl2. What mass (in g) of CaCl2 should the chemist use?
(1) 1.8 x 102 g
(2) 2.0 x 106 g
(3) 1.8 x 105 g
(4) 1.5 x 10-2 g
(5) 2.0 x 103 g
12. To what volume should you dilute 25 mL of a 10.0 M H2SO4 solution to obtain a 0.150 M H2SO4 solution?
(1) 1700 L
(2) 3800 L
(3) 1.7 L
(4) 3.75 L
(5) 0.38 L
13. Which of the following are the spectator ions for the balanced reaction below:
K2SO4(aq) + CaI2(aq) → CaSO4(s) + 2KI(aq)
(1) Ca2+, K+
(2) Ca2+, SO42-
(3) Ca2+, I-
(4) K+, SO42-
(5) K+, I-
14. What is the net ionic equation for the following balanced reaction:
NH4Cl(aq) + NaOH(aq) → H2O(l) + NH3(g) + NaCl(aq)
(1) H+(aq) + OH-(aq) → H2O(l)
(2) NH4+(aq) + OH-(aq) → H2O(l) + NH3(g)
(3) Cl-(aq) + Na+(aq) → NaCl(aq)
(4) No Reaction
(5) NH4+(aq) → H+(aq) + NH3(g)
15. Which of the following is a strong acid?
(1) HClO4
(2) HF
(3) LiOH
(4) NH3
(5) HC2H3O2
(3) Pb(CrO4)2
(4) PbCrO4
(5) Pb2CrO4
16. The correct formula for lead (II) chromate is
(1) PbCr2O7
(2) Pb2(CrO4)2
17. The name of the compound KClO
(1) Potassium Chlorate
(4) Potassium monochlorite
(2) Potassium Hypochlorite
(5) Potassium (I) hypochlorite
(3) Potassium Chlorite
18. An infant ibuprofen suspension contains 100 mg/5.0 mL suspension. The recommended dose is 10 mg/kg body
weight. How many mL of this suspension should be given to an infant weighing 18 lb? (1 lb = 453.59 g)
(1) 5.7 mL
(2) 2.0 mL
(3) 1.6 mL
(4) 3.4 mL
(5) 4.1 mL
19. A hydrate of copper (II) chloride has the following formula: CuCl2 . xH2O. The water in a 3.41 g sample of the
hydrate was driven off by heating. The remaining sample had a mass of 2.69 g. What is the value of x?
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
20. What is the minimum amount of 12.0 M H2SO4 necessary to produce 35.0 g of H2 (g) according to the following
reaction?
2 Al(s) + 3 H2SO4(aq)  Al2(SO4)3(aq) + 3 H2(g)
(1) 0.691 L
2) 4.34 L
(3) 2.92 L
(4) 1.45 L
(5) Not enough information
21. The density of a 40.0% by mass ethylene glycol (C2H6O2) solution in water is 1.11 g/mL. Find the molarity of the
solution.
(1) 7.15 M
(2) 6.44 x 10-3 M
(3) 36.0 M
(4) 0.444 M
(5) 2.78 M
22. What are the products of a general acid-base reaction?
(1) Different acids and bases
(2) Water and ammonia
(3) Water and carbon dioxide
(4) Water and hydrogen gas
(5) Water and a salt
23. What volume (in mL) of 0.400 M NaOH is required to titrate 50.00 mL of 0.10 M H2SO4 to the equivalence point?
(1) 0.0125 mL
(2) 12.5 mL
(3) 25.0 mL
(4) 5.00 mL
(5) 20.0 mL
24. Classify the following as strong electrolytes (SE), weak electrolytes (WE), or nonelectrolytes (NE):
galactose, acetic acid, hydrochloric acid, hydrofluoric acid, ammonium nitrate
(1) WE, WE SE, WE, WE
(2) NE, WE, SE, WE, SE
(3) WE, SE, SE, SE, NE
(4) WE, WE, SE, SE, SE
(5) NE, WE SE, SE, NE
25. Name the following compounds: C3H8, H-C=C-H, CH3CH2CH2CH2CH=CH2
(1) Propene, Ethene, Hexene
(2) Propane, Methene, Hexane
(3) Propyne, Methyne, Pentene
(4) Propane, Ethyne, Hexene
(5) Propane, Ethane, Hexane