AP Chem exam review

1. M+ is an unknown metal cation with a +1 charge. A student dissolves the chloride of the unknown metal, MCl, in enough water to make 100.0 mL of solution. The student then mixes the solution with excess AgNO3 solution, causing AgCl to precipitate. The student collects the precipitate by filtration, dries it, and records the data shown below. (The molar mass of AgCl is 143 g/mol.) Mass of unknown chloride, MCl 0.58 g Mass of filter paper 0.80 g Mass of filter paper plus AgCl precipitate 2.23 g What is the identity of the metal chloride? a. NaCl b. KCl c. CuCl d. LiCl

A

A 0.5 mol sample of He(g) and a 0.5 mol sample of Ne(g) are placed separately in two 10.0 L rigid containers at 25°C. Each container has a pinhole opening. Which of the gases, He(g) or Ne(g), will escape faster through the pinhole and why? a. He(g) will escape faster because the He(g) atoms are moving at a higher average speed than the Ne(g) atoms. b. Ne(g) will escape faster because its initial pressure in the container is higher. c. Ne(g) will escape faster because the Ne(g) atoms have a higher average kinetic energy than the He(g) atoms. d. Both gases will escape at the same rate because the atoms of both gases have the same average kinetic energy.

A

A 1.15 mol sample of carbon monoxide gas has a temperature of 27°C and a pressure of 0.300 atm. If the temperature were lowered to 17°C, at constant volume, what would be the new pressure? a. 0.290 atm b. 0.519 atm c. 0.206 atm d. 0.338 atm

A

A gas will behave more like an ideal gas if it has an _____ and an ___________. a. Increased volume, increased temperature b. Increased temperature, increased average kinetic energy c. Increased average kinetic energy, increased pressure d. Increased effusion rate, increased pressure

A

According to the reaction, CS2(l) + 3O2(g) à CO2(g) + 2SO2(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) a. 12 L b. 1/3 x 22.4 L c. 2 x 22.4 L d. 3 x 22.4 L

A

An anion has a charge of 2- (X2-). Which of the following correctly describes the process that resulted in that charge? a. The neutral atom gained two electrons. b. The neutral atom lost two electrons. c. The neutral atom gained two protons. d. The neutral atom lost two protons.

A

Calcium reacts with element X to form an ionic compound. If the ground-state electron configuration of X is 1s22s22p4, what is the simplest formula for this compound? a. CaX b. CaX2 c. Ca4X2 d. Ca2X2

A

For a first-order reaction of half-life 75 min, what is the rate constant in min-1? a. 0.693/75 b. 0.693/1.25 c. 0.693*75 d. 75/0.693

A

How many unpaired electrons are in the atom represented by the electron configuration 1s22s22p63s23p6 and is it diamagnetic or paramagnetic? a. 0, diamagnetic b. 0, paramagnetic c. 3, diamagnetic d. 3, paramagnetic

A

In the Lewis structure for ICl2-, how many lone pairs of electrons are around the central iodine atom? a. 3 b. 2 c. 1 d. 0

A

Magnesium nitride reacts with water to form ammonia and magnesium hydroxide. Besides water, this statement refers to which chemical formulas? a. Mg3N2, NH3, and Mg(OH)2 b. Mg(NO3)2, NH4+, and MgH2 c. Mg(NO3)2, NH3, and MgH2 d. Mg3N2, NH3, and MgOH

A

The hydrolysis of sucrose is represented by the chemical equation above. The reaction is extremely slow in aqueous solution. However, when sucrose is added as shown in the diagram, the rate of the reaction is about 6,000,000 times faster. Based on this information, which of the following best explains the large increase in the rate of hydrolysis with the addition of sucrose? a. The reaction proceeds through a different reaction path with a lower activation energy in which the sucrose-sucrose complex is formed as and intermediate. b. The addition of sucrose reduces the number of effective collisions between the water and sucrose molecules. c. The reaction proceeds through a different path that is independent of temperature and concentration. d. The addition of the sucrose decreases the number of sucrose molecules that have the minimum energy required to overcome the activation energy barrier.

A

The name of the compound CuSO4●5H2O is _______. a. Copper (II) sulfate pentahydrate b. Copper (I) sulfate pentahydrate c. Copper (II) sulfite pentahydrate d. Copper (I) sulfite pentahydrate

A

The potential energy as a function of internuclear distance for three diatomic molecules, X2, Y2, and Z2 is shown in the graph. Based on the data in the graph, which of the following correctly identifies the diatomic molecules, X2, Y2, and Z2? X2 Y2 Z2 A) H2 N2 O2 B) H2 O2 N2 C) N2 O2 H2 D) O2 H2 N2 In the graph it should be X2 looks like that then y2 is a little farther over and goes down farther then a little farther over is z2 that goes down just a little farther down than x2

A

When the following equation is balanced, it is found that 1.00 mol of C8H18 reacts with how many moles of O2? ___ C8H18 + ____ O2 à ____ CO2 + ___H2O a. 12.5 mol b. 10.0 mol c. 25.0 mol d. 37.5 mol

A

Which is a collection of only molecular compounds? a. NO, CS2, PCl3, HBr b. NaNO3, CCl4, CuS c. Ar, NH3, SF4, PCl5 d. Cl2, CCl4, NO2, SF6

A

Which of the following is expected to have the largest THIRD ionization energy? a. Be b. B c. C d. N

A

Which of the following lists of species is in order of increasing boiling points? a. H2, N2, NH3 b. N2, NH3, H2 c. NH3, H2, N2 d. NH3, N2, H2

A

Which of the following pairs are inversely proportional to each other, assuming other conditions are kept constant? a. volume, pressure b. temperature, avg. kinetic energy c. avg. kinetic energy, pressure d. effusion rate, temperature.

A

Why can a molecule of NBr5 not exist? a. Nitrogen only has 2 energy levels and is thus unable to expand its octect. b. Bromine is much larger than nitrogen and cannot be a terminal atom in this molecules. c. It is impossible to complete the octets for all six atoms using only valence electrons. d. Nitrogen does not have a low enough electronegativity to be the central atom of this molecule.

A

Why is it possible to solidify argon at a sufficiently low temperature? a. London Dispersion Forces b. Covalent Bonding c. Hydrogen Bonding d. Metallic Bonding

A

A certain crystalline substance that has a low melting point does not conduct electricity in solution or when melted. This substance is most likely to be: a. An ionic solid b. A molecular solid c. A covalent network solid d. A polymer

B

A liquid whose molecules are held together by only which of the following forces would be expected to have the lowest boiling point? a. Ionic Bonds b. London Dispersion Forces c. Hydrogen Bonds d. Metallic Bonds

B

A substance has an empirical formula of CH2. Its molar mass is determined in a separate experiment as 84. What is the most probable molecular formula for this compound? a. C2H4 b. C6H12 c. C4H2 d. CH12

B

According to the reaction, 3Ag(s) + 4HNO3(aq) à 3AgNO3(aq) + NO(g) + 2H2O(l), if 0.010 mol of powdered silver is added to 20. mL of 4 molar nitric acid, the number of moles of NO gas that can be formed is: a. 0.015 mole b. 0.0030 mole c. 0.030 mole d. 0.010 mole

B

All of the following are in aqueous solution. Which is incorrectly named? a. HC2H3O2, acetic acid b. HBr, bromic acid c. HNO2, nitrous acid d. H2SO3, sulfurous acid

B

Beginning with 96 moles of H2, how many moles of Cu(NH3)4Cl (aq) can be obtained if the synthesis of Cu(NH3)4Cl2(aq) is carried out through the following sequential reactions? Assume that a 50% yield of product(s) is (are) obtained in each reaction. 1. 3H2(g) + N2(g) à 2NH3 (g) 2. 4NH3(g) + CuSO4(aq) à Cu(NH3)4SO4(aq) 3. Cu(NH3)4SO4 +2NaCl à Cu(NH3)4Cl2(aq) + Na2SO4(aq) a. 1 b. 2 c. 4 d. 8

B

Copper atoms and zinc atoms have the same atomic radius, 135 picometers. Based on this information, which of the following diagrams best represents an alloy containing only copper and zinc atoms? A. one atom smaller and shaded, other atom bigger and not shaded B. all atoms same size some shaded others not C. big atoms shaded with negative charge, small atoms not shaded with positive charge D. all atoms the same size all shaded *sorry could not insert pic*

B

Given that there are two, common isotopes of chlorine, one with a mass of 35 and one with a mass of 37, which of the following correctly predicts the number of peaks that will be observed in the mass spectrum for singular, chlorine atoms (Cl), and the number of peaks in the mass spectrum for diatomic chlorine gas (Cl2)? a. 2 for atomic Cl and 2 for diatomic Cl2 b. 2 for atomic Cl and 3 for diatomic Cl2 c. 2 for atomic Cl and 4 for diatomic Cl2 d. 3 for atomic Cl and 3 for diatomic Cl2

B

How many of the following molecules possess dipole moments? BH3, CH4, CO2, H2O, HF, H2 a. 1 b. 2 c. 3 d. 4

B

The complete PES of the element carbon is represented with equal sized peaks. Which of the following best explains how the spectrum is consistent with the electron shell model of the atom? a. The spectrum shows 4 electrons in the inner electron shell b. The spectrum shows equal numbers of electrons in the three occupied electron subshells c. The spectrum shows that all the electrons in the valence shell have the same binding energy d. The spectrum shows more electrons in the inner electron shell than in the outer electron shell.

B

The complete photoelectron spectrum of an element is given. Which labeled peak corresponds to the "1s" electrons and why? a. Peak X (O), because "1s" electrons are the easiest to remove from the atom b. Peak X (O) because "1s" electrons have the strongest attractions to the nucleus c. Peak Y (N) because electrons in the "1s" sublevel are the farthest from the nucleus d. Peak Y (N) because there are fewer electrons in an s sublevel than in a p sublevel *DISCLAIMER i cannot put my own pictures in here because i dont have quizlet pro so only the pics that should up on quizlet work sorry*

B

The decomposition of O3(g) in the upper atmosphere is represented by the equation: O3(g) + O(g) à 2O2(g). The potential energy diagram for the decomposition of O3(g) in the presences and absence of NO(g) is given below. *Imagine dotted line being a two-step line* Which of the following mechanisms for the catalyzed reaction is consistent with the equation and diagram above? A) 2O3+2NO-->4O2+N2 slow B) O3+NO-->NO2+O2 slow NO2+O-->NO+O2 fast C) NO2+O3-->NO+2O2 slow NO+O-->NO2 fast D) NO2+O-->NO3 slow NO3+O3-->NO2+2O2 fast

B

The dissociation of XY molecules, 2XY(g) à X2(g) + Y2(g), occurs at a temperature of 800 K. The rate constant, k=6.0 x 10-3s-1. What is the reaction order? a. 0 b. 1 c. 2 d. 3

B

The following questions refer to the 1 L flasks shown below. Which flask contains the smallest number of moles? A. N2: T=30C P=1atm B. N2: T=50C P=0.5atm C. O2: T=40C P=2 atm D. O2: T=50C P=1 atm

B

The reaction between NO(g) and O2(g) to produce NO2(g) in a rigid reaction vessel is represented in the diagram above. The pressure inside the container is recorded using a pressure gauge. Which of the following statements correctly predicts the change in pressure as the reaction goes to completion at constant temperature, and provides the correct explanation? a. The pressure will increase because the product molecules have a greater mass than either of the reactant molecules. b. The pressure will decrease because there are fewer molecules of product than of reactants. c. The pressure will decrease because the product molecules have a lower average speed than the reactant molecules. d. The pressure will not change because the total mass of the product molecules is the same as the total mass of the reactant molecules.

B

VSEPR predicts an SbF5 molecule will be which of the following shapes? a. Tetrahedral b. Trigonal bipyramidal c. Square pyramid d. Trigonal planar

B

What is the name and formula of the compound shown in the diagram to the right? a. H2CO3; carbonous acid b. H2CO3; carbonic acid c. H2CO3; dihydrogen carbonate d. H3CO2; triydrogen carbon dioxide

B

What is the pressure of the gas based on the reading of the open-tube manometer to the right? (Atmospheric pressure=763 mmHg, h=3.5 cm) a. 798 mmHg b. 728 mmHg c. 1940 mmHg d. 218 mmHg

B

When free Cl(g) atoms encounter O3(g) molecules in the upper atmosphere in an exothermic reaction, the following reaction mechanism is proposed to occur. Cl(g)+O3(g)-->ClO(g)+O2(g) slow step ClO(g)+O3(g)-->Cl(g)+2O2(g) fast step 2O3(g)--> 3O2(g) overall reaction 1. Which of the following rate laws for the overall reaction corresponds to the proposed mechanism? a. Rate=k[O3]2 b. Rate=k[Cl][O3] c. Rate=k[ClO][O3]2 d. Rate=k[O2]/[O3]

B

Which of the following bonds would have the largest dipole moment? a. C-Si b. O-C c. S-C d. C-N

B

Which of the following compounds would have the highest lattice energy? a. LiF b. MgCl2 c. CaBr2 d. C2H6

B

Which of the following molecules will have a Lewis dot structure with exactly one unshared electron pair on the central atom? a. H2O b. PH3 c. PCl5 d. CH2Cl

B

Which of the following nuclei has 3 more neutrons than protons? a. Boron-11 b. Chlorine-37 c. Magnesium-24 d. Gallium-70

B

Which of the following reaction energy profiles best corresponds to the proposed 2nd order mechanism? A) second graph B) first graph

B

Which of the following statements is true? a. Neon and magnesium are chemically similar because they both have full s sublevels. b. Helium and argon are chemically similar because they both have full valence levels. c. Sodium and argon are chemically similar because they both have electrons in the third energy level. d. Aluminum and chlorine are chemically similar because they both contain 3p sublevel electrons.

B

The reaction between solutions sodium chlorate and mercury (I) iodate results in the formation of the precipitate, mercury (I) chlorate. Which of the following is the correct net ionic equation for the reaction? a. NaClO3 (aq) + HgIO3 (aq) à HgClO3 (s) + NaIO3(aq) b. NaClO2 (aq) + HgIO2(aq) à HgClO2 (s) + NaIO2(aq) c. Hg+(aq) + ClO3- (aq)à HgClO3(s) d. Hg+(aq) + ClO2- (aq) à HgClO2(s)

C

A 0.35 g sample of Li(s) is placed in an Erlenmeyer flask containing 100 mL of water at 25°C. A balloon is placed over the mouth of the flask to collect the hydrogen gas that is generated. Which of the following changes will most likely increase the rate of reaction between Li(s) and water? a. Using 125 mL of water instead of 100 mL b. Using a 0.25 g sample of Li(s) instead of a 0.35 g sample c. Using 0.35 g sample of Li(s) cut into small pieces d. Decreasing the water temperature before adding the Li(s)

C

A compound contains 48.0% O, 40.0% Ca, and the remainder is C. What is its empirical formula? a. O3C2Ca2 b. O2CCa2 c. O3CCa d. O3CCa2

C

A sample of Neon gas is sealed in a container. The volume of the container is doubled. If the pressure remains constant, what happens to the absolute temperature? a. It does not change. b. It is halved. c. It is doubled. d. It is squared.

C

Aluminum metal reacts with HCl to produce aluminum chloride and hydrogen gas. How many grams of aluminum metal must be added to an excess of HCl to produce 33.6 L of hydrogen gas, if the gas is at STP? a. 18.0 g b. 35.0 g c. 27.0 g d. 4.50 g

C

How many electrons are available to construct the Lewis structure of the sulfite ion? a. 24 b. 18 c. 26 d. 22

C

Identify the element in period 2 that has the following successive ionization energies, measured in kJ/mol. 1st IE- 1314 kJ/mol 2nd IE- 3389 kJ/mol 3rd IE- 5298 kJ/mol 4th IE- 7471 kJ/mol 5th IE- 10992 kJ/mol 6th IE- 13329 kJ/mol 7th IE- 71345 kJ/mol 8th IE- 84087 kJ/mol a. Li b. B c. O d. Ne

C

Mass spectrometry, when applied to elements, is used to collect evidence for what feature of atomic structure? a. Electronic configuration b. Molecular rotation c. Isotopic abundance d. Electronic transitions

C

The electron pairs point towards the corners of which geometrical shape for a molecule with sp2 hybrid orbitals? a. Octahedron b. Trigonal bipyramid c. Trigonal planar d. Trigonal pyramid

C

The elements I and Te have similar average atomic masses. A sample that was believed to be a mixture of I and Te was run through a mass spectrometer, resulting in the data above. All of the following statements are true. Which one would be the best basis for concluding that the sample was pure Te? a. Te forms ions with a -2 charge, whereas I forms ions with a -1 charge. b. Te is more abundant than I in the universe c. I consist of only one naturally occurring isotope with 74 neutrons, whereas Te has more than one isotope. d. I has a higher first ionization energy than Te does. (Chart contains has many mass numbers with with isotopes in each one)

C

The only substance below that contains ionic, sigma and pi bonds is: a. HClO2 b. H2O c. Na2CO3 d. NaCl

C

The rate expression for a third-order reaction could be: a. Rate=k[X] b. Rate=k[X][Y] c. Rate=k[X]2[Y] d. Rate= k[X]2[Y]2

C

The rate law of a certain reaction is rate=k[X][Y]. The units of k, with time measured in seconds, is a. s-1 b. M-2s-1 c. M-1s-1 d. M-1

C

The volume of a sample of air in a cylinder with a movable piston is 2.0 L at a pressure P1. The volume is increased to 5.0 L as the temperature is held constant. The pressure of the air in the cylinder is now P2. What effect do the volume and pressure changes have on the average kinetic energy of the molecules in the sample? a. The average kinetic energy increases. b. The average kinetic energy decreases. c. The average kinetic energy stays the same. d. It cannot be determined how the kinetic energy is affected without knowing P1 and P2.

C

Under certain conditions, the average rate of appearance of oxygen gas in the reaction 2O3(g) --> 3O2(g) is 6.00 torr s-1. What is the average rate expressed in units of torr s-1 for the disappearance of O3? a. 9.0 b. 6.0 c. 4.0 d. 3.0

C

When 4.0 L of He(g), 6.0 L of N2(g) and 10.L of Ar(g), all at 0°C and 1.0 atm, are pumped into an evacuated 8.0 L rigid container, the final pressure in the container at 0°C is a. 0.5 atm b. 1.0 atm c. 2.5 atm d. 4.0 atm

C

Which of the following best helps explain the trend of increasing atomic radius from N to Bi? a. The number of particles in the nucleus of the atom increases b. The number of electrons in the outermost shell of the atom increases c. The attractive force between the valence electrons and nuclei of the atom decreases. d. The repulsive force between the valence electrons and the electrons in the inner shells decreases.

C

Which of the following best helps explain why the first ionization energy of K is less than that of Ca? a. The electronegativity of K is greater than that of Ca b. The atomic radius of the K atom is less than that of the Ca atom c. The valence electron of K experience a lower effective nuclear charge than the valence electrons of Ca d. The nucleus of K atom has fewer neutrons, on average, than the nucleus of the Ca atom has.

C

Which of the following particulate diagrams best shows the formation of water vapor from hydrogen gas and oxygen gas in a rigid container at 125 C? AGAIN could only put right answer sorry

C

Which of these molecules has the largest bond angle? a. PF5 b. NH3 c. HCN d. SO3

C

Which of these molecules has the most pi bonds? a. PF5 b. NH3 c. HCN d. SO3

C

A gas in a 1.50 L container has a pressure of 245 mmHg. When the gas is transferred completely to a 350. mL container at the same temperature, the pressure will be a. 1.05 mmHg b. 1.05 atm c. 2.14 mmHg d. 1050 mmHg

D

A reaction produces a gaseous mixture of carbon dioxide, carbon monoxide, and water vapor. After one reaction, the mixture was analyzed and found to contain 0.60 mol of carbon dioxide, 0.30 mol of carbon monoxide, and 0.10 mol of water vapor. If the total pressure of the mixture was 0.80 atm, what was the partial pressure of the carbon monoxide? a. 0.080 atm b. 0.34 atm c. 0.13 atm d. 0.24 atm

D

An ionic compound has the unit formula of X3Z2. Which of the following correctly identifies the appropriate charges on the ions in this compound? a. X3+, Z2- b. X3-, Z2+ c. X2-, Z3+ d. X2+, Z3- (These answers have these numbers as exponents)

D

Atoms with very similar electronegativity values are expected to form____. a. No bonds b. Ionic bonds c. Triple bonds d. Covalent bonds

D

For irreversible chemical reactions the rate will be affected by changes in all of these factors, EXCEPT: a. Temperature b. Concentration of reactants c. Presence of a catalyst d. Concentration of products

D

Frequency Wavelength Energy X= 3x10^21 1x10^-13 2x10^-12 Y= 3x10^14 ? ? Two types of electromagnetic radiation, X and Y, are represented in the data table above. Which of the following are the most probable values for wavelength and energy associated with Y? a. 1x 10-20 m, 2 x 10-5 J b. 1 x 10-20 m, 2 x 10-19 J c. 1 x 10-6 m, 2 x 10-5 J d. 1 x 10-6 m, 2 x 10-19 J

D

If the curves represented one gas at four different temperatures, which curve would represent the highest temperature? A. purple B. green C. blue D. red

D

In general, atomic radii decrease from left to right across a period. The main reason for this behavior is a. The number of neutrons in the nucleus increases b. The number of electrons increases c. The atomic mass increases d. The effective nuclear charge increases

D

In order to determine the order of the reaction, X(g) + 2Y(g) à 2XY2(g), the initial rate of formation of XY2 is measured using different initial values of [X] and [Y]. The results of the experiment are shown in the table below. [X] [Y] Rate of Formation 1) 0.50 0.50 8.0x10^-3 2) 1.00 0.50 3.2x10^-2 3) 1.00 1.00 6.4x10^-2 In trial 2, which of the reactants would be consumed more rapidly, and why? a. X, because it has a higher molar concentration. b. X, because the reaction is second order with respect to X. c. Y, because the reaction is second order with respect to Y. d. Y, because the rate of disappearance will be double that of X.

D

In the cyanide ion, CN-, the nitrogen atom has a formal charge of ___________. a. 2 b. 1 c. -1 d. 0

D

In the ionic compound with the general formula M2X3, the likely group that element M is located in is a. Group 1 (1A) b. Group 2 (2A) c. Group 12 (12B) d. Group 13 (3A)

D

In your lab, "The Analysis of Alum," the melting point of your Alum crystals established the ______ of those crystals by comparing the melting point to _____________. a. Percent sulfate, experimental values b. Waters of hydration, literature values c. Purity, experimental values d. Purity, literature values

D

The diagrams to the right represent solutes present in two different dilute aqueous solutions before they were mixed. Water molecules are not shown. When the solutions were combined, a precipitation reaction took place. Which of the diagrams below is the best particle representation of the mixture after the precipitation reaction occurred? *I can only put one picture and thats the right one sorryyyy*

D

The graph to the right shows the distribution of molecular speeds for four different gases at the same temperature. What property of the different gases can be correctly ranked using the information from the graph and why? a. The densities of the gases, because as the density of a gas increases, the average speed of its molecule decreases. b. The pressures of the gases, because the pressure exerted by a gas depends on the average speed with which its molecules are moving. c. The volumes of the gases, because at a fixed temperature the volume of a gas can be calculated using the equation PV=nRT d. The molecular masses of the gases, because the gas molecules have the same kinetic energy and mass can be calculated using the equation KEavg=1/2mv2

D

The rate law for the reaction of nitrogen dioxide and chlorine is found to be rate=k[NO2]2[Cl2]. By what factor does the rate of the reaction change when the concentrations when both NO2 and Cl2 are doubled? a. 2 b. 3 c. 6 d. 8

D

What are the spectator ions in the balanced equation for the reaction between sodium hydroxide and copper (II) sulfate? a. 2Na+(aq) + 2OH-(aq) + Cu2+(aq) + SO42-(aq) b. 2Na+(aq) + 2OH-(aq) c. Cu2+(aq) + SO42-(aq) d. 2Na+(aq) + SO42-(aq)

D

Which of the following best explains why 1-butanol, CH3CH2CH2CH2OH, has a higher surface tension than its isomer, diethyl ether, CH3CH2OCH2CH3? a. The higher density of 1-butanol b. The lower specific heat of 1-butanol c. The lack of hydrogen bonding in 1-butanol d. The presence of hydrogen bonding in 1-butanol.

D

Which of the following choices of atoms and ions is consistent with the electron configuration 1s22s22p63s23p6? a. He, Ne, Ar b. Fl-, Cl-, Ar c. K+, Na+, Cl-, F- d. K+, Cl-, Ar

D

Which of the following electron configurations most likely represents an atom that will form an anion? a. [Kr] 5s1 b. [Kr] 5s2 c. [Kr] 5s2 4d9 d. [Kr] 5s2 4d10 5p5

D

Which of the following electron configurations represents the ground state of an element? a. [Ne]3s13p1 b. [He]2s12p3 c. [Ne]3s23p33d1 d. [Ne]3s23p3

D

Which of the following isoelectric species has the smallest radius? a. O2- b. F- c. Ne d. Na+

D

Which of the following molecules would exhibit the strongest dipole moment? a. CH4 b. BCl3 c. PBr5 d. OF2

D

Why does CaF2 have a higher melting point than NH3? a. CaF2 is more massive and thus has stronger London dispersion forces. b. CaF2 exhibits network covalent bonding, which is the strongest type of bonding. c. CaF2 is smaller and exhibits greater Coulombic attractive forces. d. CaF2 is an ionic substance and it requires a lot of energy to break up an ionic lattice.

D