Form A
AP Chemistry Spring 2010 Test #2
Read all the questions carefully
Do not write on this test.
Check your work.
Good Luck
25. A sample of 3.30 grams of an ideal gas at 150.0_C and 1.25 atmospheres pressure has a volume of 2.00 liters. What is the molar mass of the gas? The gas constant, R, is 0.0821 (L.atm)/(mol.K).
(A)0.0218 gram/mole(B)16.2 grams/mole
(C)37.0 grams/mole(D)45.8 grams/mole
(E)71.6 grams/mole
26. Samples of F2 gas and Xe gas are mixed in a container of fixed volume. The initial partial pressure of the F2 gas is 8.0 atmospheres and that of the Xe gas is 1.7 atmospheres. When all of the Xe gas reacted, forming a solid compound, the pressure of the unreacted F2 gas was 4.6 atmospheres. The temperature remained constant. What is the formula of the compound?
(A)XeF(B)XeF3(C)XeF4
(D)XeF6(E)XeF8
27. A sample of an ideal gas is cooled from 50.0_C to 25.0_C in a sealed container of constant volume. Which of the following values for the gas will decrease?
I.The average molecular mass of the gas
II.The average distance between the molecules
III.The average speed of the molecules
(A)I only(B)II only(C)III only
(D)I and III(E)II and III
28.Which of the following acids can be oxidized to form a stronger acid?
(A)H3PO4(B)HNO3(C)H2CO3
(D)H3BO3(E)H2SO3
29.What volume of 0.150–molar HCl is required to neutralize 25.0 milliliters of 0.120–molar Ba(OH)2?
(A)20.0 mL(B)30.0 mL(C)40.0 mL
(D)60.0 mL(E)80.0 mL
30. When a 1.00–gram sample of limestone was dissolved in acid, 0.38 gram of CO2 was generated. If the rock contained no carbonate other than CaCO3, what was the percent of CaCO3 by mass in the limestone?
(A)17%(B)51%(C)64%
(D)86%(E)100%
31.The net ionic equation for the reaction between silver carbonate and hydrochloric acid is
(A)Ag2CO3(s) + 2 H+ + 2 Cl– 2 AgCl(s) + H2O + CO2(g)
(B)2 Ag+ + CO32– + 2 H+ + 2 Cl– 2 AgCl(s) + H2O + CO2(g)
(C)CO32– + 2 H+ H2O + CO2(g)
(D)Ag+ + Cl– AgCl(s)
(E)Ag2CO3(s) + 2 H+ 2 Ag+ + H2CO3
32.Which of the following species CANNOT function as an oxidizing agent?
(A) Cr2O72–(C) NO3–(E) I–
(B) MnO4–(D) S
33. Ca, V, Co, Zn, As
Gaseous atoms of which of the elements above are paramagnetic?
(A)Ca and As only(D)V, Co, and As only
(B)Zn and As only(E)V, Co, and Zn only
(C)Ca, V, and Co only
34. A student wishes to prepare 2.00 liters of 0.100–molar KIO3 (molecular weight 214). The proper procedure is to weigh out
(A)42.8 grams of KIO3 and add 2.00 kilograms of H2O
(B)42.8 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters
(C)21.4 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters
(D)42.8 grams of KIO3 and add 2.00 liters of H2O
(E)21.4 grams of KIO3 and add 2.00 liters of H2O
35. When the actual gas volume is greater then the volume predicted by the ideal gas law, the explanation lies in the fact that the ideal gas law does NOT include a factor for molecular.
(A) volume(C) velocity(E) shape
(B) mass(D) attractions
36. Gaseous mixture containing 7.0 moles of nitrogen, 2.5 moles of oxygen, and 0.50 mole of helium exerts a total pressure of 0.90 atmosphere. What is the partial pressure of the nitrogen?
a. 0.13 atmc. 0.63 atme. 6.3 atm
b. 0.27 atmd. 0.90 atm
37. Hydrogen gas is collected over water at 24OC. The total pressure of the sample is 755 millimeters of mercury. At 24OC, the vapor pressure of water is 22 millimeters of mercury. What is the partial pressure of the hydrogen gas?
a. 22 mm Hg c. 755 mm Hge. 777 mm Hg
b. 733 mm Hg d. 760 mm Hg
38. All of the following species can function as Brönsted–Lowry bases in solution EXCEPT
a. H2Oc. S2–e. HCO3–
b. NH3d. NH4+
39. 2 K + 2 H2O 2K++ 2 OH– + H2
When 0.400 mole of potassium reacts with excess water at standard temperature and pressure as shown in the equation above, the volume of hydrogen gas produced is
a. 1.12 litersc. 3.36 literse. 6.72 liters
b. 2.24 litersd. 4.48 liters
40. The test for the presence of Ag+ in an unknown solution involves the treatment of the silver–ammonia complex with dilute hydrochloric acid. The appearance of a white precipitate at this point indicates the presence of silver ion in the original sample. The net ionic equation that represents this test is
a. Ag(NH4)4+ + 4 H+ Ag(s) + 4 NH4+
b. Ag(NH4)4+ + Cl– AgCl(s) + 4 NH4+
c. Ag(NH3)4++4HCl AgCl(s) +4NH4++3Cl–
d. Ag(NH3)2+ + Cl– Ag(NH3)2Cl(s)
e. Ag(NH3)2+ + 2 H+ + Cl– AgCl(s) + 2 NH4+
41. 2 H2O + 4 MnO4– + 3 ClO2– 4 MnO2 + 3 ClO4– + 4 OH–
Which species acts as an oxidizing agent in the reaction represented above?
(A)H2O(B)ClO4–(C)ClO2–
(D)MnO2(E)MnO4–
42. Concentrations of colored substances are commonly measured by means of a spectrophotometer. Which of the following would ensure that correct values are obtained for the measured absorbance?
I.There must be enough sample in the tube to cover the entire light path.
II.The instrument must be periodically reset using a standard.
III.The solution must be saturated.
(A)I only(B)II only
(C)I and II only(D)II and III only
(E)I, II, and III
43. When dilute nitric acid was added to a solution of one of the following chemicals, a gas was evolved. This gas turned a drop of limewater, Ca(OH)2, cloudy, due to the formation of a white precipitate. The chemical was
(A)household ammonia, NH3
(B)baking soda, NaHCO3
(C)table salt, NaCl
(D)epsom salts, MgSO4.7H2O
(E)bleach, 5% NaOCl
44. When a sample of oxygen gas in a closed container of constant volume is heated until its absolute temperature is doubled, which of the following is also doubled?
(A) The density of the gas
(B) The pressure of the gas
(C) The average velocity of the gas molecules
(D) The number of molecules per cm3
(E) The potential energy of the molecules
FRQ (12 points)
1996 D (Required)
Represented above are five identical balloons, each filled to the same volume at 25C and 1.0 atmosphere pressure with the pure gases indicated.
(a)Which balloon contains the greatest mass of gas? Explain.
(b)Compare the average kinetic energies of the gas molecules in the balloons. Explain.
(c)Which balloon contains the gas that would be expected to deviate most from the behavior of an ideal gas? Explain.
(d)Twelve hours after being filled, all the balloons have decreased in size. Predict which balloon will be the smallest. Explain your reasoning.