AP Chemistry: Units 1-4 MCQ Practice
Sodium chloride is LEAST soluble in which of the following liquids? A H2O B CCl4 C HF D CH3OH E CH3COOH
B
Forms monatomic ions with 2- charge in solutions A F B S C Mg D Ar E Mn
B S
2 SO2(g) + O2(g) → 2 SO3(g) A mixture of gases containing 0.20 mol of SO2 and 0.20 mol of O2 in a 4.0 L flask reacts to form SO3. If the temperature is 25ºC, what is the pressure in the flask after reaction is complete?
0.3(0.082)(298)/4 atm
CS2(l) + 3 O2(g) → CO2(g) + 2 SO2(g) What volume of O2(g) is required to react with excess CS2(l) to produce 4.0 L of CO2(g)? (Assume all gases are measured at 0°C and 1 atm.)
12 L
6 on Unit 4 2 KClO3 (s)−→−−MnO2Δ2 KCl (s)+3 O2 (g) According to the equation above, how many moles of potassium chlorate, KClO3 , must be decomposed to generate 1.0 L of O2 gas at standard temperature and pressure?
2/3(1/22.4) mol
2 H2O(l) + 4 MnO4-(aq) + 3 ClO2-(aq) → 4 MnO2(s) + 3 ClO4-(aq) + 4 OH-(aq) According to the balanced equation above, how many moles of ClO2-(aq) are needed to react completely with 20. mL of 0.20 M KMnO4 solution? A 0.0030 mol B 0.0053 mol C 0.0075 mol D 0.013 mol E 0.030 mol
A
2 N2H4(g) + N2O4(g) → 3 N2(g) + 4 H2O(g) When 8.0 g of N2H4 (32 g mol-1) and 92 g of N2O4 (92 g mol-1) are mixed together and react according to the equation above, what is the maximum mass of H2O that can be produced? A 9.0 g B 18 g C 36 g D 72 g E 144 g
A
3 Ag(s) + 4 HNO3 → 3 AgNO3 + NO(g) + 2 H2O The reaction of silver metal and dilute nitric acid proceeds according to the equation above. If 0.10 mole of powdered silver is added to 10. milliliters of 6.0-molar nitric acid, the number of moles of NO gas that can be formed is A 0.015 mole B 0.020 mole C 0.030 mole D 0.045 E 0.090
A
32 Unit 3 Based on the data in the tables above, which of the following statements provides the best prediction for the boiling point of NaCl? A NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF. B NaCl will have a boiling point between that of NaF and MgO because the covalent character of the bonds in NaCl is intermediate between that of MgO and NaF. C NaCl will have a higher boiling point than MgO because the ions are spaced farther apart in NaCl. D NaCl will have a higher boiling point than MgO because the energy required to transfer electrons from the anion to the cation is larger in NaCl than in MgO.
A
An oxidation-reduction reaction that is also a synthesis reaction A 2 Mg(s) + O2(g) → 2 MgO(s) B Pb2+(aq) + CrO42-(aq) → PbCrO4(s) C SO3(g) + 2 H2O(l) → H3O+(aq) + HSO4-(aq) D 2 H2O(g) → 2 H2(g) + O2(g) E Ag+(aq) + 2 NH3(aq) → [Ag(NH3)2]+(aq)
A
At standard temperature and pressure, a 0.50 mol sample of H2 gas and a separate 1.0 mol sample of O2 gas have the same A average molecular kinetic energy B average molecular speed C volume D effusion rate E density
A
HC2H3O2(aq) + CN-(aq) ⇄ HCN(aq) + C2H3O2-(aq) The reaction represented above has an equilibrium constant equal to 3.7 x 104. Which of the following can be concluded from this information? A CN-(aq) is a stronger base than C2H3O2-(aq). B HCN(aq) is a stronger acid than HC2H3O2(aq). C The conjugate base of CN-(aq) is C2H3O2-(aq). D The equilibrium constant will increase with an increase in temperature. E The pH of a solution containing equimolar amounts of CN-(aq) and HC2H3O2 (aq) is 7.0.
A
If 0.40 mol of H2 and 0.15 mol of O2 were to react as completely as possible to produce H2O, what mass of reactant would remain? A 0.20 g of H2 B 0.40 g of H2 C 3.2 g of O2 D 4.0 g of O2 E 4.4 g of O2
A
If 200. mL of 0.60 M MgCl2(aq) is added to 400. mL of distilled water, what is the concentration of Mg2+(aq) in the resulting solution? (Assume volumes are additive). A 0.20 M B 0.30 M C 0.40 M D 0.60 M E 1.2 M
A
NH4NO3(s) → N2O(g) + 2 H2O(g) A 0.03 mol sample of NH4NO3(s) is placed in a 1 L evacuated flask, which is then sealed and heated. The NH4NO3(s) decomposes completely according to the balanced equation above. The total pressure in the flask measured at 400 K is closest to which of the following? (The value of the gas constant, R, is 0.082 L atm mol-1 K-1.) A 3 atm B 1 atm C 0.5 atm D 0.1 atm E 0.03 atm
A
On the basis of strength of intermolecular forces, which of the following elements would be expected to have the highest melting point? A Br2 B Cl2 C F2 D Kr E N2
A
The London (dispersion) forces are weakest for which of the following gases under the same conditions of temperature and pressure? A H2 B O2 C Xe D F2 E
A
The boiling points of the elements helium, neon, argon, krypton, and xenon increase in that order. Which of the following statements accounts for this increase? A The London (dispersion) forces increase. B The hydrogen bonding increases. C The dipole-dipole forces increase. D The chemical reactivity increases. E The number of nearest neighbors increases.
A
W(g) + X(g) → Y(g) + Z(g) Gases W and X react in a closed, rigid vessel to form gases Y and Z according to the equation above. The initial pressure of W(g) is 1.20 atm and that of X(g) is 1.60 atm. No Y(g) or Z(g) is initially present. The experiment is carried out at constant temperature. What is the partial pressure of Z(g) when the partial pressure of W(g) has decreased to 1.0 atm? A 0.20 atm B 0.40 atm C 1.0 atm D 1.2 atm E 1.4 atm
A
When 100 mL of 1.0 M Na3PO4 is mixed with 100 mL of 1.0 M AgNO3, a yellow precipitate forms and [Ag+] becomes negligibly small. Which of the following is a correct listing of the ions remaining in solution in order of increasing concentration? A [PO43-] < [NO3-] < [Na+] B [PO43-] < [Na+] < [NO3-] C [NO3-] < [PO43-] < [Na+] D [Na+] < [NO3-] < [PO43-] E [Na+] < [PO43-] < [NO3-]
A
When the actual gas volume is greater than 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 B mass C velocity D attractions E shape
A
Which of the following gases deviates most from ideal behavior? A SO2 B Ne C CH4 D N2 E H2
A
A solution is prepared by adding 16 g of CH3OH (molar mass 32 g) to 90. g of H2O (molar mass 18 g). The mole fraction of CH3OH in this solution is closest to which of the following? A 0.1 B 0.2 C 0.3 D 0.4 E 0.6
A 0.1
How many carbon atoms are contained in 2.8 g of C2H4 ? A 1.2 x 1023 B 3.0 x 1023 C 6.0 x 1023 D 1.2 x 1024 E 6.0 x 1024
A 1.2 x 1023
Which of the following represents the ground state electron configuration for the Mn3+ ion? (Atomic number Mn = 25) A 1s2 2s22p6 3s23p63d4 B 1s2 2s22p6 3s23p63d5 4s2 C 1s2 2s22p6 3s23p63d2 4s2 D 1s2 2s22p6 3s23p63d8 4s2 E 1s2 2s22p6 3s23p63d3 4s1
A 1s2 2s22p6 3s23p63d4
The electron-dot structure (Lewis structure) for which of the following molecules would have two unshared pairs of electrons on the central atom? A H2S B NH3 C CH4 D HCN E CO2
A H2S
Which of the following molecules has the shortest bond length? A N2 B O2 C Cl2 D Br2 E I2
A N2
Has molecules with a pyramidal shape A NH3(g) B BH3(g) C H2(g) D H2S(g) E HBr(g)
A NH3(g)
Consider atoms of the following elements. Assume that the atoms are in the ground state. The atom that contains exactly two unpaired electrons A S B Ca C Ga D Sb E Br
A S
H - C ≡ C - H What is the hybridization of the carbon atoms in a molecule of ethyne, represented above? A sp B sp2 C sp3 D dsp2 E d2sp
A sp
2 Al(s) + 6 HCl(aq) → 2 AlCl3(aq) + 3 H2(g) According to the reaction represented above, about how many grams of aluminum (atomic mass 27 g) are necessary to produce 0.50 mol of hydrogen gas at 25ºC and 1.00 atm? A 1.0 g B 9.0 g C 14 g D 27 g E 56 g
B
25 on Unit 4 Refer to the following. PCl5(g) ⇄ PCl3(g)+Cl2(g) PCl5(g) decomposes into PCl3(g) and Cl2(g) according to the equation above. A pure sample of PCl5(g) is placed in a rigid, evacuated 1.00L container. The initial pressure of the PCl5(g) is 1.00 atm. The temperature is held constant until the PCl5(g) reaches equilibrium with its decomposition products. The figures below show the initial and equilibrium conditions of the system. If the decomposition reaction were to go to completion, the total pressure in the container will be A 1.4 atm B 2.0 atm C 2.8 atm D 3.0 atm
B
27 Unit 3 On the basis of the solubility curves shown above, the greatest percentage of which compound can be recovered by cooling a saturated solution of that compound from 90°C to 30°C? A NaCl B KNO3 C K2CrO4 D K2SO4 E Ce2(SO4)3
B
A 20.0-milliliter sample of 0.200-molar K2CO3 solution is added to 30.0 milliliters of 0.400-molar Ba(NO3)2 solution. Barium carbonate precipitates. The concentration of barium ion, Ba2+, in solution after reaction is A 0.150 M B 0.160 M C 0.200 M D 0.240 M E 0.267 M
B
A precipitation reaction A 2 Mg(s) + O2(g) → 2 MgO(s) B Pb2+(aq) + CrO42-(aq) → PbCrO4(s) C SO3(g) + 2 H2O(l) → H3O+(aq) + HSO4-(aq) D 2 H2O(g) → 2 H2(g) + O2(g) E Ag+(aq) + 2 NH3(aq) → [Ag(NH3)2]+(aq)
B
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
B
Approximately what mass of CuSO4 • 5H2O (250 g mol-1) is required to prepare 250 mL of 0.10 M copper(II) sulfate solution? A 4.0 g B 6.2 g C 34 g D 85 g E 140 g
B
Unit 3 MCQ Practice 21 Refer to three gases in identical rigid containers under the conditions given in the table below. The density of the gas, in g/L, is A greatest in container A B greatest in container B C greatest in container C D the same in all three containers
B
What mass of Au is produced when 0.0500 mol of Au2S3 is reduced completely with excess H2? A 9.85 g B 19.7 g C 24.5 g D 39.4 g E 48.9 g
B
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
B
Which of the following describes the changes in forces of attraction that occur as H2O changes phase from a liquid to a vapor? A H - O bonds break as H - H and O - O bonds form. B Hydrogen bonds between H2O molecules are broken. C Covalent bonds between H2O molecules are broken. D Ionic bonds between H+ ions and OH- ions are broken. E Covalent bonds between H+ ions and H2O molecules become more effective.
B
Which of the following is the conjugate acid of NH2- ? A NH2- B NH3 C H+ D NH4+ E H2O
B
Which of the following pieces of laboratory glassware should be used to most accurately measure out a 25.00 mL sample of a solution? A 5 mL pipet B 25 mL pipet C 25 mL beaker D 25 mL Erlenmeyer flask E 50 mL graduated cylinder
B
Of the following electron configurations of neutral atoms, which represents an atom in an excited state? A 1s2 2s2 2p5 B 1s2 2s2 2p5 3s2 C 1s2 2s2 2p6 3s1 D 1s2 2s2 2p6 3s2 3p2 E 1s2 2s2 2p6 3s2 3p5
B 1s2 2s2 2p5 3s2
Which of the following best helps to account for the fact that the F- ion is smaller than the O2- ion? A F- has a larger nuclear mass than O2- has. B F- has a larger nuclear charge than O2- has. C F- has more electrons than O2- has. D F- is more electronegative than O2- is. E F- is more polarizable than O2- is.
B F- has a larger nuclear charge than O2- has.
The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+. II. O2- is more negatively charged than F-. III. The O2- ion is smaller than the F- ion. A II only B I and II only C I and III only D II and III only E I, II, and III
B I and II only
The effective nuclear charge experienced by the outermost electron of Na is different than the effective nuclear charge experienced by the outermost electron of Ne. This difference best accounts for which of the following? A Na has a greater density at standard conditions than Ne. B Na has a lower first ionization energy than Ne. C Na has a higher melting point than Ne. D Na has a higher neutron-to-proton ratio than Ne. E Na has fewer naturally occurring isotopes than Ne.
B Na has a lower first ionization energy than Ne.
Which of the following molecules has an angular (bent) geometry that is commonly represented as a resonance hybrid of two or more electron-dot structures? A CO2 B O3 C CH4 D BeF2 E OF2
B O3
Which of the following shows the correct number of protons, neutrons, and electrons in a neutral cesium-134 atom? A ProtonsNeutronsElectrons555555 B ProtonsNeutronsElectrons557955 C ProtonsNeutronsElectrons557979 D ProtonsNeutronsElectrons795579 E ProtonsNeutronsElectrons13455134
B ProtonsNeutronsElectrons557955
After completing an experiment to determine gravimetrically the percentage of water in a hydrate, a student reported a value of 38 percent. The correct value for the percentage of water in the hydrate is 51 percent. Which of the following is the most likely explanation for this difference? A Strong initial heating caused some of the hydrate sample to spatter out of the crucible. B The dehydrated sample absorbed moisture after heating. C The amount of the hydrate sample used was too small. D The crucible was not heated to constant mass before use. E Excess heating caused the dehydrated sample to decompose.
B The dehydrated sample absorbed moisture after heating.
In which of the following compounds is the mass ratio of chromium to oxygen closest to 1.62 to 1.00? A CrO3 B CrO2 C CrO D Cr2O E Cr2O3
B CrO2
. . . C10H12O4S(s) + . . . O2(g) → . . . CO2(g) + . . . SO2(g) + . . . H2O(g) When the equation above is balanced and all coefficients are reduced to their lowest whole-number terms, the coefficient for O2(g) is A 6 B 7 C 12 D 14 E 28
C
19 on Unit 3 MCQ Practice Refer to three gases in identical rigid containers under the conditions given in the table below. If the pressure of each gas is increased at constant temperature until condensation occurs, which gas will condense at the lowest pressure? A Methane B Ethane C Butane D All the gases will condense at the same pressure.
C
28 on Unit 4 The diagram above represents H2(g) and N2(g) in a closed container. Which of the following diagrams would represent the results if the reaction shown below were to proceed as far as possible? N2(g) + 3 H2(g) → 2 NH3(g) A B C D E Related Content & Skills Topic4.3 SkillSkill 3.B
C
32 in Unit 4 K(s)+ ½ Cl2(g) → KCl(s) ΔH° = -437kJ/molrxn The elements K and Cl react directly to form the compound KCl according to the equation above. Refer to the information above and the table below to answer the questions that follow. What remains in the reaction vessel after equal masses of K(s) and Cl2(g) have reacted until either one or both of the reactants have been completely consumed? A KCl only B KCl and K only C KCl and Cl2 only D KCl, K, and Cl2
C
36 Unit 3 Nonane and 2,3,4-trifluoropentane have almost identical molar masses, but nonane has a significantly higher boiling point. Which of the following statements best helps explain this observation? A The C-F is easier to break than the C-H bond. B The C-F is more polar than the C-H bond. C The carbon chains are longer in nonane than they are in 2,3,4-trifluoropentane. D The carbon chains are farther apart in a sample of nonane than they are in 2,3,4-trifluoropentane.
C
36 in Unit 4 Which of the following particulate diagrams best shows the formation of water vapor from hydrogen gas and oxygen gas in a rigid container at 125oC? A B C D
C
43 Unit 3 Refer to the following. PCl5(g) ⇄ PCl3(g)+Cl2(g) PCl5(g) decomposes into PCl3(g) and Cl2(g) according to the equation above. A pure sample of PCl5(g) is placed in a rigid, evacuated 1.00L container. The initial pressure of the PCl5(g) is 1.00 atm. The temperature is held constant until the PCl5(g) reaches equilibrium with its decomposition products. The figures below show the initial and equilibrium conditions of the system. Which of the following is the most likely cause for the increase in pressure observed in the container as the reaction reaches equilibrium? A A decrease in the strength of intermolecular attractions among molecules in the flask B An increase in the strength of intermolecular attractions among molecules in the flask C An increase in the number of molecules, which increases the frequency of collisions with the walls of the container D An increase in the speed of the molecules that then collide with the walls of the container with greater force
C
A 1.0 L sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of CaCl2. What is the minimum number of moles of AgNO3 that must be added to the solution in order to precipitate all of the Cl- as AgCl(s) ? (Assume that AgCl is insoluble.) A 0.10 mol B 0.20 mol C 0.30 mol D 0.40 mol E 0.60 mol
C
A 2 L container will hold about 4 g of which of the following gases at 0°C and 1 atm? A SO2 B N2 C CO2 D C4H8 E NH3
C
A 40.0 mL sample of 0.25 M KOH is added to 60.0 mL of 0.15 M Ba(OH)2. What is the molar concentration of OH-(aq) in the resulting solution? (Assume that the volumes are additive.) A 0.10 M B 0.19 M C 0.28 M D 0.40 M E 0.55 M
C
A rigid metal tank contains oxygen gas. Which of the following applies to the gas in the tank when additional oxygen is added at constant temperature? A The volume of the gas increases. B The pressure of the gas decreases. C The average speed of the gas molecules remains the same. D The total number of gas molecules remains the same. E The average distance between the gas molecules increases.
C
A sample of an ideal gas is cooled from 50.0oC to 25.0oC 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
C
Equal masses of three different ideal gases, X, Y, and Z, are mixed in a sealed rigid container. If the temperature of the system remains constant, which of the following statements about the partial pressure of gas X is correct? A It is equal to ⅓ the total pressure B It depends on the intermolecular forces of attraction between molecules of X, Y, and Z. C It depends on the relative molecular masses of X, Y, and Z. D It depends on the average distance traveled between molecular collisions. E It can be calculated with knowledge only of the volume of the container.
C
N2 molecules absorb ultraviolet light but not visible light. I2 molecules absorb both visible and ultraviolet light. Which of the following statements explains the observations? A More energy is required to make N2 molecules vibrate than is required to make I2 molecules vibrate. B More energy is required to remove an electron from an I2 molecule than is required to remove an electron from a N2 molecule. C Visible light does not produce transitions between electronic energy levels in the N2 molecule but does produce transitions in the I2 molecule. D The molecular mass of I2 is greater than the molecular mass of N2.
C
Of the following organic compounds, which is LEAST soluble in water at 298 K? A CH3OH, methanol B CH3CH2CH2OH, l-propanol C C6H14, hexane D C6H12O6, glucose E CH3COOH, ethanoic (acetic) acid
C
The best explanation for the fact that diamond is extremely hard is that diamond crystals A are made up of atoms that are intrinsically hard because of their electronic structures B consist of positive and negative ions that are strongly attracted to each other C are giant molecules in which each atom forms strong covalent bonds with all of its neighboring atoms D are formed under extreme conditions of temperature and pressure E contain orbitals or bands of delocalized electrons that belong not to single atoms but to each crystal as a whole
C
Under which of the following conditions of temperature and pressure would 1.0 mol of the real gas CO2(g) behave most like an ideal gas? A Temperature(K)Pressure(atm)1000.1 B Temperature(K)Pressure(atm)100100 C Temperature(K)Pressure(atm)8000.1 D Temperature(K)Pressure(atm)8001 E Temperature(K)Pressure(atm)800100
C
Graph in 15 on Unit 1 MCQ Practice The ionization energies for element X are listed in the table above. On the basis of the data, element X is most likely to be A Na B Mg C Al D Si E P
C Al
Which of the following molecules contains only single bonds? A CH3COOH B CH3CH2COOCH3 C C2H6 D C6H6 E HCN
C C2H6
Which of the following is a nonpolar molecule that contains polar bonds? A F2 B CHF3 C CO2 D HCl E NH3
C CO2
Graph in Unit w MCQ Practice To make Au stronger and harder, it is often alloyed with other metals, such as Cu and Ag. Consider two alloys, one of Au and Cu and one of Au and Ag, each with the same mole fraction of Au. If the Au/Cu alloy is harder than the Au/Ag alloy, then which of the following is the best explanation based on the information in the table above? A Cu has two common oxidation states, but Ag has only one. B Cu has a higher melting point than Au has, but Ag has a lower melting point than Au has. C Cu atoms are smaller than Ag atoms, thus they interfere more with the displacement of atoms in the alloy. D Cu atoms are less polarizable than are Au or Ag atoms, thus Cu has weaker interparticle forces. Related Content & Skills Topic2.4
C Cu atoms are smaller than Ag atoms, thus they interfere more with the displacement of atoms in the alloy.
Consider atoms of the following elements. Assume that the atoms are in the ground state. The atom that contains only one electron in the highest occupied energy sublevel A S B Ca C Ga D Sb E Br
C Ga
When hafnium metal is heated in an atmosphere of chlorine gas, the product of the reaction is found to contain 62.2 percent Hf by mass and 37.4 percent Cl by mass. What is the empirical formula for this compound? A HfCl B HfCl2 C HfCl3 D HfCl4 E Hf2Cl3
C HfCl3
A compound contains 1.10 mol of K, 0.55 mol of Te, and 1.65 mol of O. What is the simplest formula of this compound? A KTeO B KTe2O C K2TeO3 D K2TeO6 E K4TeO6
C K2TeO3
Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Contains 1 sigma (σ) and 2 pi (π) bonds A Li2 B B2 C N2 D O2 E F2
C N2
Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Has the largest bond-dissociation energy A Li2 B B2 C N2 D O2 E F2
C N2
Of the following single bonds, which is the LEAST polar? A N—H B H—F C O—F D I—F E O—H
C O—F
A compound contains 30. percent sulfur and 70. percent fluorine by mass. The empirical formula of the compound is A SF B SF2 C SF4 D SF6 E S2F
C SF4
Which of the following ions has the same number of electrons as Br - ? A Ca2+ B K+ C Sr2+ D I- E Cl-
C Sr2+
15 on Unit 2 MCQ Practice The hybridization of the carbon atoms in the molecule represented above can be described as A sp B sp2 C sp3 D dsp2 E d2sp Related Content & Skills Topic2.7 SkillSkill 1.A
C sp3
Which reaction is one in which the same reactant undergoes both oxidation and reduction? a. H2SeO4(aq) + 2Cl-(aq) + 2H+(aq) --> H2SeO3(aq) + Cl2(g) + H2O(l) b. Sg(s) + 8O2(g) --> 8SO2(g) c. 3Br2(aq) + 6OH-(aq) --> 5Br-(aq) + BrO3-(aq) + 3H2O(l) d. Ca2+(aq) + SO42-(aq) --> CaSO4(s) e. PtCl4(s) + 2Cl-(aq) --> PtCl62-(aq) C. 3Br2(aq) + 6OH-(aq) --> 5Br-(aq) + BrO3-(aq) + 3H2O(l)
C. 3Br2(aq) + 6OH-(aq) --> 5Br-(aq) + BrO3-(aq) + 3H2O(l)
. . . Ca3(PO4)2(s) + . . . H3PO4(l) → . . . Ca(H2PO4)2(s) When the equation above is balanced and all coefficients are reduced to lowest whole-number terms, what is the coefficient for H3PO4(l) ? A 1 B 2 C 3 D 4 E 5
D
10 HI + 2 KMnO4 + 3 H2SO4 → 5 I2 + 2 MnSO4 + K2SO4 + 8 H2O According to the balanced equation above, how many moles of HI would be necessary to produce 2.5 mol of I2, starting with 4.0 mol of KMnO4 and 3.0 mol of H2SO4 ? A 20. B 10. C 8.0 D 5.0 E 2.5
D
20 on Unit 3 MCQ Practice Refer to three gases in identical rigid containers under the conditions given in the table below. The average kinetic energy of the gas molecules is A greatest in container A B greatest in container B C greatest in container C D the same in all three containers
D
A 0.10 M aqueous solution of sodium sulfate, Na2SO4 , is a better conductor of electricity than a 0.10 M aqueous solution of sodium chloride, NaCl. Which of the following best explains this observation? A Na2SO4 is more soluble in water than NaCl is. B Na2SO4 has a higher molar mass than NaCl has. C To prepare a given volume of 0.10 M solution, the mass of Na2SO4 needed is more than twice the mass of NaCl needed. D More moles of ions are present in a given volume of 0.10 M Na2SO4 than in the same volume of 0.10 M NaCl. E The degree of dissociation of Na2SO4 in solution is significantly greater than that of NaCl.
D
A 360. mg sample of aspirin, C9H8O4, (molar mass 180. g), is dissolved in enough water to produce 200. mL of solution. What is the molarity of aspirin in a 50. mL sample of this solution? A 0.0800 M B 0.0400 M C 0.0200 M D 0.0100 M E 0.00250 M
D
A sealed vessel contains 0.200 mol of oxygen gas, 0.100 mol of nitrogen gas, and 0.200 mol of argon gas. The total pressure of the gas mixture is 5.00 atm. The partial pressure of the argon is A 0.200 atm B 0.500 atm C 1.00 atm D 2.00 atm E 5.00 atm
D
At constant temperature, the behavior of a sample of a real gas more closely approximates that of an ideal gas as its volume is increased because the A collisions with the walls of the container become less frequent B average molecular speed decreases C molecules have expanded D average distance between molecules becomes greater E average molecular kinetic energy decrease
D
Directions: Each set of lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. The following questions refer to the reactions represented below. (A) H2SeO4(aq) + 2 Cl-(aq) + 2 H+(aq) → H2SeO3(aq) + Cl2(g) + H2O(l)(B) S8(s) + 8 O2(g) → 8 SO2(g)(C) 3 Br2(aq) + 6 OH-(aq) → 5 Br-(aq) + BrO3-(aq) + 3 H2O(l)(D) Ca2+(aq) + SO42-(aq) → CaSO4(s)(E) PtCl4(s) + 2 Cl-(aq) → PtCl62-(aq) A precipitation reaction A H2SeO4(aq) + 2 Cl-(aq) + 2 H+(aq) → H2SeO3(aq) + Cl2(g) + H2O(l) B S8(s) + 8 O2(g) → 8 SO2(g) C 3 Br2(aq) + 6 OH-(aq) → 5 Br-(aq) + BrO3-(aq) + 3 H2O(l) D Ca2+(aq) + SO42-(aq) → CaSO4(s) E PtCl4(s) + 2 Cl-(aq) → PtCl62-(aq)
D
H2Se(g) + 4 O2F2(g) → SeF6(g) + 2 HF(g) + 4 O2(g) Which of the following is true regarding the reaction represented above? A The oxidation number of O does not change. B The oxidation number of H changes from -1 to +1. C The oxidation number of F changes from +1 to -1. D The oxidation number of Se changes from -2 to +6. E It is a disproportionation reaction for F.
D
How many mL of 10.0 M HCl are needed to prepare 500. mL of 2.00 M HCl ? A 1.00 mL B 10.0 mL C 20.0 mL D 100. mL E 200. mL
D
In which of the following processes are covalent bonds broken? A I2(s) → I2(g) B CO2(s) → CO2(g) C NaCl(s) → NaCl(l) D C(diamond) → C(g) E Fe(s) → Fe(l)
D
The volume of distilled water that should be added to 10.0 mL of 6.00 M HCl(aq) in order to prepare a 0.500 M HCl(aq) solution is approximately A 50.0 mL B 60.0 mL C 100. ML D 110. ML E 120. mL
D
When 70. milliliter of 3.0-molar Na2CO3 is added to 30. milliliters of 1.0-molar NaHCO3 the resulting concentration of Na+ is A 2.0 M B 2.4 M C 4.0 M D 4.5 M E 7.0 M
D
What number of moles of O2 is needed to produce 14.2 grams of P4O10 from P? (Molecular weight P4O10 = 284) A 0.0500 mole B 0.0625 mole C 0.125 mole D 0.250 mole E 0.500 mole
D 0.250 mole
A sample of CaCO3 (molar mass 100. g) was reported as being 30. percent Ca. Assuming no calcium was present in any impurities, the percent of CaCO3 in the sample is A 30% B 40% C 70% D 75% E 100%
D 75%
Directions: Each set of lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. The following questions refer to the below molecules: (A) CO2(B) H2O(C) CH4(D) C2H4(E) PH3 The molecule with only one double bond A CO2 B H2O C CH4 D C2H4 E PH3
D C2H4
Of the following molecules, which has the largest dipole moment? A CO B CO2 C O2 D HF E F2
D HF
Which of the following represents a pair of isotopes? Atomic Number | Mass Number A I. 6 | 14 II. 7 | 14 B I. 6 | 7 II. 14 | 14 C I. 6 | 14 II. 14 | 28 D I. 7 | 13 II. 7 | 14 E I. 8 | 10 II. 16 | 20
D I. 7 | 13 II. 7 | 14
5 on Unit 1 MCQ Practice The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum? A Nitrogen atoms have a half-filled p subshell. B There are more electron-electron repulsions in oxygen atoms than in nitrogen atoms. C Electrons in the p subshell of oxygen atoms provide more shielding than electrons in the p subshell of nitrogen atoms. D Nitrogen atoms have a smaller nuclear charge than oxygen atoms. Related Content & Skills Topic1.6 SkillSkill 4.A Related Videos 1.6: Daily Video 1 1.6: Daily Video 2 The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum? A Nitrogen atoms have a half-filled p subshell. B There are more electron-electron repulsions in oxygen atoms than in nitrogen atoms. C Electrons in the p subshell of oxygen atoms provide more shielding than electrons in the p subshell of nitrogen atoms. D Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
D Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Has a bond order of 2 A Li2 B B2 C N2 D O2 E F2
D O2
According to the VSEPR model, the progressive decrease in the bond angles in the series of molecules CH4, NH3, and H2O is best accounted for by the A increasing strength of the bonds B decreasing size of the central atom C increasing electronegativity of the central atom D increasing number of unshared pairs of electrons E decreasing repulsion between hydrogen atoms
D increasing number of unshared pairs of electrons
2 MnO4-(aq) + 10 Br-(aq) + 16 H+(aq) → 2 Mn2+(aq) + 5 Br2(aq) + 8 H2O(l) How many electrons are transferred in the reaction represented by the balanced equation above? A 2 B 4 C 5 D 8 E 10
E
5 Fe2+ + MnO4- + 8 H+ ⇄ 5 Fe3+ + Mn2+ + 4 H2O In a titration experiment based on the equation above, 25.0 milliliters of an acidified Fe2+ solution requires 14.0 milliliters of standard 0.050-molar MnO4- solution to reach the equivalence point. The concentration of Fe2+ in the original solution is A 0.0010 M B 0.0056 M C 0.0028 M D 0.0090 M E 0.14 M
E
A flask contains 0.25 mole of SO2(g), 0.50 mole of CH4(g), and 0.50 mole of O2(g). The total pressure of the gases in the flask is 800 mm Hg. What is the partial pressure of the SO2(g) in the flask? A 800 mm Hg B 600 mm Hg C 250 mm Hg D 200 mm Hg E 160 mm Hg
E
CH3—CH2—CH2—CH2—CH3- X CH3—CH2—CH2—CH2—OH- Y HO—CH2—CH2—CH2—OH- Z X Y Z Based on concepts of polarity and hydrogen bonding, which of the following sequences correctly lists the compounds above in the order of their increasing solubility in water? A Z < Y < X B Y < Z < X C Y < X < Z D X < Z < Y E X < Y < Z
E
Equal masses of He and Ne are placed in a sealed container. What is the partial pressure of He if the total pressure in the container is 6 atm? A 1 atm B 2 atm C 3 atm D 4 atm E 5 atm
E
HSO4- + H2O ⇌ H3O+ + SO42- In the equilibrium represented above, the species that act as bases include which of the following? I. HSO4- II. H2O III. SO42- A II only B III only C I and II D I and III E II and III
E
In solid methane, the forces between neighboring CH4 molecules are best characterized as A ionic bonds B covalent bonds C hydrogen bonds D ion-dipole forces E London (dispersion) forces
E
In which of the following species does sulfur have the same oxidation number as it does in H2SO4? A H2SO3 B S2O32- C S2- D S8 E SO2Cl2
E
Is a strong electrolyte in aqueous solution A NH3(g) B BH3(g) C H2(g) D H2S(g) E HBr(g)
E
The liquefied hydrogen halides have the normal boiling points given above. The relatively high boiling point of HF can be correctly explained by which of the following? A HF gas is more ideal. B HF is the strongest acid. C HF molecules have a smaller dipole moment. D HF is much less soluble in water. E HF molecules tend to form hydrogen bonds.
E
Two flexible containers for gases are at the same temperature and pressure. One holds 0.50 gram of hydrogen and the other holds 8.0 grams of oxygen. Which of the following statements regarding these gas samples is FALSE? A The volume of the hydrogen container is the same as the volume of the oxygen container. B The number of molecules in the hydrogen container is the same as the number of molecules in the oxygen container. C The density of the hydrogen sample is less than that of the oxygen sample. D The average kinetic energy of the hydrogen molecules is the same as the average kinetic energy of the oxygen molecules. E The average speed of the hydrogen molecules is the same as the average speed of the oxygen molecules.
E
Which of the following represents a process in which a species is reduced? A Ca(s) → Ca2+(aq) B Hg(l) → Hg22+(aq) C Fe2+(aq) → Fe3+(aq) D NO3-(aq) → NO(g) E SO32-(aq) → SO42-(aq)
E
Which of the following techniques is most appropriate for the recovery of solid KNO3 from an aqueous solution of KNO3? A Paper chromatography B Filtration C Titration D Electrolysis E Evaporation to dryness
E
Equal masses of He and Ne are placed in a sealed container. What is the partial pressure of He if the total pressure in the container is 6 atm? A 1 atm B 2 atm C 3 atm D 4 atm E 5 atm
E 5 atm
Which of the following properties generally decreases across the periodic table from sodium to chlorine? A First ionization energy B Atomic mass C Electronegativity D Maximum value of oxidation number E Atomic radius
E Atomic radius
Pi (π) bonding occurs in each of the following species EXCEPT A CO2 B C2H4 C CN- D C6H6 E CH4
E CH4
Of the following compounds, which is the most ionic? A SiCl4 B BrCl C PCl3 D Cl2O E CaCl2
E CaCl2
The elements in which of the following have most nearly the same atomic radius? A Be, B, C, N B Ne, Ar, Kr, Xe C Mg, Ca, Sr, Ba D C, P, Se, I E Cr, Mn, Fe, Co
E Cr, Mn, Fe, Co
1s2 2s2 2p6 3s2 3p3 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is A MgX B Mg2X C MgX2 D MgX3 E Mg3X2
E Mg3X2
Which of the following species is NOT planar? A CO32- B NO3- C ClF3 D BF3 E PCl3
E PCl3
Which of the following has a zero dipole moment? A HCN B NH3 C SO2 D NO2 E PF5
E PF5
Directions: Each set of lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. The following questions refer to the below molecules: (A) CO2(B) H2O(C) CH4(D) C2H4(E) PH3 The molecule that has trigonal pyramidal geometry A CO2 B H2O C CH4 D C2H4 E PH3
E PH3
The geometry of the SO3 molecule is best described as A trigonal planar B trigonal pyramidal C square pyramidal D bent E tetrahedral
a trigonal planar
