Chem 121.09 Winter 2012 Exam III
Name ___________________________________________________
Multiple Choice Questions. Give the one best answer for each question.
____1. Which of the following reactions is both correct and balanced?
A) N2 + H3 = 2NH3
B) 2H2O + CO = CO2 + 2H2
C) Zn + 2HCl = H2 + ZnCl2
D) CO + O2 = CO2
____2. Which species would be considered a spectator ion based on the following equation?
Ba2+ + 2NO3 + 2Na+ + SO42+ = BaSO4(s) + 2NO3- + 2Na+
A) Ba2+
B) SO42+
C) BaSO4
D) 2NO3____3. How many grams of N2 are required to completely react with 3.03 grams of H2 for the
following balanced chemical equation?
N2 + 3H2 = 2NH3
A) 1.00
B) 6.00
C) 14.0
D) 28.0
____4. Which is not a meaning of oxidation?
A) to gain electrons
B) to lose hydrogen
C) to combine with oxygen
D) to lose electrons
____5. 2500 liters of oxygen gas is produced at 1.00 atm of pressure. It is to be compressed and
stored in a 20.0 liter cylinder. If temperature is constant, calculate the pressure of the
oxygen in the cylinder.
A) 125 atm B) 4.0 atm C) 80.0 atm
D) 8.00 atm
____6. A gas sample has a volume of 500 mL at 20oC. At what Celsius temperature would the gas
have a volume half as large?
A) 10oC
B) 147oC
C) -147oC
D) -127oC
____7. What pressure will 3.20 mol of N2 gas exert if confined in a 15.0 L container at 100oC?
R = 0.0821 Latm/molK
A) 1.75 atm
B) 6.53 atm C) 3.27 atm D) 13.0 atm
____8. Which of the following gases is least likely to behave ideally?
A) He
B) N2
C) HCl
D) H2
____9. Which of the following gases would diffuse slower than O2?
A) HCl
B) H2
C) He
D) Cl2
____10. In which of the following processes does the kinetic energy of the water increase?
A) water freezes
B) steam condenses to liquid
C) water evaporates
D) more than one response is correct
____11. Which of the following is an exothermic process?
A) Sublimation [(s) to (g)]
B) melting
C) evaporation
D) condensation
____12. The vapor pressure of a liquid
A) decreases with increasing temperature
B) is independent of temperature
C) is equal to one atmosphere at the normal boiling point
D) cannot be measured
____13. Which of the following is not a standard condition (STP) for gas measurements?
A) 0OC
B) 1.00 atm
C) 273 K
D) 1.00 torr
____14. In a chemical reaction, you were able to produce 1.345 g of product although it was
theoretically possible to make 1.433 g. What was the percent yield for this synthesis? Use
the correct number of significant figures.
A) 93.859 %
B) 93.86 %
C) 94 %
D) 0.9386 %
____15. A salt sample is placed into water and stirred until no more will dissolve. The resulting
solution is
A) saturated
B) supersaturated C) unsaturated D) can't tell from the data given
____16. Which of the solutes below can most likely dissolve better if an aqueous solution is
heated?
A) oxygen B) sodium bicarbonate C) argon D) more than one correct response is
given
____17. Iodine, I2, is very slightly soluble in water, a polar solvent, but quite soluble in toluene, a
nonpolar solvent. What can be inferred about the nature of the I2 molecule?
A) It is ionic. B) It is polar. C) It is nonpolar. D) Nothing can be inferreD)
____18. When solid NaOH is dissolved in water, the solution becomes hot. The solution process is
A) exothermic B) endothermic C) neither exo nor endothermic D) can't be classified
____19. A solution is made by dissolving 5.84 grams of NaCl in enough distilled water to give a
final volume of 1.00 L. What is the molarity of the solution?
A) 0.100
B) 1.00
C) 0.0250
D) 0.400
____20. How many moles of Na2CO3 would be needed to react with 750 mL of 0.250 M H2SO4
solution?
Na2CO3 + H2SO4 = Na2SO4 + CO2 + H2O
A) 3.00 X 103
B) 0.333
C) 1.33
D) 0.188
____21. A solution is made by combining 4.00 g of sugar and 100 mL of water (density = 1.00
g/mL). What is the concentration in % w/w?
A) 26.0
B) 4.00
C) 0.0400
D) 3.85
____22. A solution is made by dissolving 15.0 mL of oil in enough gasoline to give 50.0 mL of
solution. What is the % (v/v) of oil in the solution?
A) 30.0
B) 23.1
C) 42.9
D) 3.33
____23. How many mL of 6.00 M HCl are needed to prepare 1500 mL of 0.200 M HCl solution?
A) 1.80 X 104 B) 125 C) 2.00 X 10-3 D) 50.0
____24. The boiling point of a solution of sugar water is
A) higher than that of pure solvent B) the same as that of pure solvent
C) lower than that of pure solvent D) impossible to determine
____25. Two solutions with concentrations of 2% sugar and 4% sugar, respectively, are separated
by a semipermeable membrane. During osmosis, there is a net flow of
A) sugar molecules from the concentrated to the dilute solution
B) sugar molecules from the dilute to the concentrated solution
C) water molecules from the concentrated to the dilute solution
D) water molecules from the dilute to the concentrated solution
____26. Compared to pure water, a salt water solution will have a
A) lower vapor pressure, freezing point and boiling point
B) higher vapor pressure, freezing point and boiling point
C) lower vapor pressure and freezing point and a higher boiling point
D) higher freezing point and a lower vapor pressure and boiling point
____35. Which of the following pass through both osmotic and dialysis membranes?
A) water molecules
B) large molecules
C) small molecules that are larger than water molecules
D) more than one response is correct
____36. Which of the following is not considered a colligative property?
A) vapor pressure B) boiling point C) conductivity D) freezing point
____37. Which of the following would be considered a strong electrolyte?
A) NaCl B) sugar C) acetic acid D) all of the choices
38. A) Write and balance an equation where methane (CH4) reacts with oxygen to form
carbon dioxide and water.
38. B) Give an example of a product of the reaction.
38. C) Which reactant is the oxidizing agent?
39. Consider the following reaction.
4HCl + MnO2 = Cl2 + 2H2O + MnCl2
If MnO2 is defined as the oxidizing agent, what is the ..
Reducing agent?
Substance being oxidized?
Substance being reduced?
40. NaHCO3 solution and HCl solution react together to form carbon dioxide, water and
NaCl solution. Write 3 balanced chemical equations to represent this reaction – a
“molecular”, a total ionic and a net ionic. Include the descriptors of (aq), (s), (g), etc as
appropriate.
41. Consider two gases at the same temperature – He with an atomic mass of 4 and O2 with
a mass of 32. Part of the kinetic molecular theory states that all gases have the same
kinetic energy at a given temperature. How is this possible since these gases differ so
greatly in mass? (one or two sentences should suffice.)
42. Match each reaction below as A) combination/synthesis B) decomposition C) single
displacement D) double displacement E) redox F) non-redox. Each equation will have
two correct answers.
_________AgNO3 + NaCl = AgCl + NaNO3
_________C + O2 = CO2
_________2SO2 + O2 = 2SO3
_________CaCO3 = CaO + CO2
43. Describe how a colloid is similar to a true solution and also how it is different from a
true solution. Two or three sentences should suffice.