CAS CH 28141 | Course Paper

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If an ionic solid has a face-centered cubic lattice of anions (Xn–) and all the octahedral

holes are occupied by metal cations (Mm+), what is the formula for the compound?

A.M2X

B.MX

C.MX2

D.M2X3

E.M3X2

A 25.0 mL sample of 0.10 M sodium benzoate is titrated with 0.10 M HCl(aq). What is

the pH after the addition of 32.0 mL of HCl(aq)? (Kb of C6H5CO2

“ = 1.6 10“10)

A.1.00

B.1.25

C.1.91

D.4.20

E.9.79

Which of the following compounds is a weak acid?

A.HCl

B.H3PO4

C.HNO3

D.HClO4

E.H2SO4

The standard free energy change associated with the dissolution of ammonium nitrate in

water is “6.73 kJ/mol at 298.15 K.

NH4NO3(s) NH4NO3(aq)

What is the equilibrium constant for the reaction? (R = 8.314 J/Kmol)

A.1.9 10“3

B.6.6 10“2

C.1.0

D.15

E.5.2 102

Which one of the following aqueous solutions will have a pH of 2.00 at 25 C? (Kw =

1.01 10“14)

A.0.020 M HNO3

B.2.0 M NaOH

C.10.0 M HBr

D.10.0 M KCl

E.0.010 M HCl

Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of

sulfur dioxide, XeF4.

A.The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral.

B.The electron-pair geometry is octahedral, the molecular geometry is tetrahedral.

C.The electron-pair geometry is tetrahedral, the molecular geometry is octahedral.

D.The electron-pair geometry is octahedral, the molecular geometry is square-planar.

E.The electron-pair geometry is square-planar, the molecular geometry is tetrahedral.

Which of the following compounds are soluble in water: K2CO3, CaCO3, NiCO3, and

Fe2(CO3)3?

A.K2CO3 only

B.K2CO3 and CaCO3

C.CaCO3 and NiCO3

D.NiCO3 and Fe2(CO3)3

E.CaCO3, NiCO3, and Fe2(CO3)3

All of the following sets of quantum numbers are allowed EXCEPT

A.n = 5, = 3, = +2

B.n = 4, = 2, = “1

C.n = 3, = 0, = 0

D.n = 2, = 0, = +1

E.n = 2, = 1, = 0

If the ground state electron configuration of an element is [Ar]3d104s24p5, what is the

typical charge on the monatomic anion of the element?

A.4+

B.2+

C.1″

D.2″

E.3″

Nitrogen dioxide reacts with carbon monoxide to produce nitrogen monoxide and

carbon dioxide.

NO2(g) + CO(g) NO(g) + CO2(g)

A proposed mechanism for this reaction is

2 NO2(g) NO3(g) + NO(g) (fast, equilibrium)

NO3(g) + CO(g) NO2(g) + CO2(g) (slow)

What is a rate law that is consistent with the proposed mechanism?

A.rate = k[NO2]2[CO] [NO]“1

B.rate = k[NO2]2[CO]

C.rate = k[NO2][CO]

D.rate = k[NO3][CO]

E.rate = k[NO2]2

Which of the following statements is/are CORRECT?

1/ Specific heat capacity is a positive value for liquids and solids and a negative value

for gases.

2/ The larger the heat capacity of an object, the more thermal energy it can store.

3/ When heat is transferred from the surroundings to the system, q is negative.

A.1 only

B.2 only

C.3 only

D.1 and 2

E.1, 2, and 3

A hot piece of iron is dropped into a beaker containing colder water. Which of the

following statements is/are CORRECT?

1/ Energy is transferred as heat from the iron to the water.

2/. Thermal equilibrium is attained when the iron and the water reach the same

temperature.

3/ Thermal energy from the iron is converted to electrostatic energy in the water.

A.1 only

B.2 only

C.3 only

D.1 and 2

E.1, 2, and 3

Given the following equilibria,

PbBr2(s) Pb2+(aq) + 2 Br“(aq) K1 = 6.6 10“6

Pb(OH)2(s) Pb2+(aq) + 2 OH“(aq) K2 = 1.4 10“15

determine the equilibrium constant, Kc, for the following reaction.

PbBr2(s) + 2 OH“(aq) Pb(OH)2(s) + 2 Br“(aq)

A.9.2 10“21

B.2.1 10“10

C.6.6 10“6

D.4.7 109

E.1.1 1020

What is the formula for potassium diamminetetrachlorovanadate(III)?

A.[KV(NH3)2Cl4]

B.K2[V(NH3)2Cl4]

C.K[V(NH3)2Cl4]

D.[KV(NH3)2]Cl4

E.K[V(NH3)2]Cl4

Which equation represents the number of atoms in a primitive cubic unit cell?

Magnesium reacts with iodine gas at high temperatures to form magnesium iodide.

What mass of MgI2 can be produced from the reaction of 5.15 g Mg and 50.0 g I2?

A.29.5 g

B.44.9 g

C.54.8 g

D.55.2 g

E.58.9 g

What intermolecular force or bond is primarily responsible for the solubility of CH3OH

in water?

A.ion-dipole force

B.dipole-dipole force

C.ionic bonding

D.covalent bonding

E.hydrogen bonding

Estimate the boiling point of ethanol given the following thermodynamic parameters.

C2H5OH( ) C2H5OH(g)

DfH (kJ/mol) “277.0 “235.3

S (J/Kmol) 160.7 282.7

DfG (kJ/mol) “174.7 “168.5

A.22 C

B.44 C

C.61 C

D.69 C

E.91 C

for the following galvanic cell is “1.80 V.

Fe2+(aq) + 2 Cl“(aq) Fe(s) + Cl2(g)

What is DrG for this reaction?

A.”174 kJ

B.86.8 kJ

C.107 kJ

D.174 kJ

E.347 kJ

Transmittance, T, is defined as the intensity of light transmitted through a sample

divided by the intensity of light incident on the sample. The absorbance, A, is defined as

A.A = “log T

B.A = log (“T)

C.A = 10T

D.A = 10“T

E.A = 10“1/T

Which element has the following ground state electron configuration?

A.B

B.O

C.C

D.Be

E.Si

Which of the following regions of the electromagnetic spectrum have longer

wavelengths than visible light?

1/ infrared radiation

2/ ultraviolet radiation

3/ microwave radiation

A.1 only

B.2 only

C.3 only

D.1 and 2

E.1 and 3

If a metal crystallizes in a face-centered cubic lattice, each metal atom has ____

“nearest neighbors.”

A.3

B.4

C.6

D.8

E.12

Which one of the following processes involves an increase in the entropy of the

system?

A.3 H2(g) + N2(g) 2 NH3(g)

B.N2(g) + 2 O2(g) 2 NO2(g)

C.2 Ag2O(s) 4 Ag(s) + O2(g)

D.CaO(s) + CO2(g) CaCO3(s)

E.2 Na(s) + Cl2(g) 2 NaCl(s)

At an elevated temperature, the equilibrium constant, Kc, for the following reaction is

54.

H2(g) + I2(g) 2 HI(g)

If the equilibrium concentrations of H2 and I2 are 0.025 mol/L and 0.017 mol/L, what is

the equilibrium concentration of HI?

A.5.3 10“4 M

B.2.8 10“3 M

C.0.023 M

D.0.15 M

E.6.6 M

Which of the following compounds is expected to have the strongest ionic bonds?

A.RbI

B.KCl

C.NaBr

D.CsF

E.LiF

Write the expression for K for the reaction below.

Co2(CO3)3(s) 2 Co3+(aq) + 3 CO3

2″(aq)

Which of the following processes is/are endothermic?

1/ the combustion of hydrogen

2/ the condensation of water

3/ the evaporation of isopropyl alcohol

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2, and 3

If an element can be obtained profitably from a mineral, the mineral is called a(n) ____.

A.gangue

B.ore

C.slag

D.roast

E.alloy

For a primitive cubic unit cell, what percentage of the space in the cell is occupied by

the atoms at the corners of the cell?

A.47%

B.52%

C.68%

D.74%

E.87%

What mass of KCl (molar mass = 74.55 g/mol) must be added to 1.0 L of 0.0180 M

Pb2+(aq) to initiate precipitation of PbCl2(s)? The Ksp of PbCl2 is 1.7 10“5. Assume no

volume change occurs upon addition of KCl.

A.6.6 10“5 g

B.0.041 g

C.0.070 g

D.2.3 g

E.2.5 g

Which of the following statements is/are CORRECT?

1/ Absorbance is directly proportional to the intensity of the incident light.

2/ Absorbance is inversely proportional to the analyte concentration.

3/ Absorbance is directly proportional to the path length of the light.

A.1 only

B.2 only

C.3 only

D.2 and 3

E.1,2, and 3

Which element has the highest density?

A.Zn

B.Y

C.Os

D.Fe

E.Ag

Which one of the following statements is INCORRECT?

A.Energy is neither created nor destroyed in chemical reactions.

B.Kinetic energy is the energy that results from an object’s position.

C.Exothermic processes transfer heat from the system into the surroundings.

D.Increasing the thermal energy of a gas increases the motion of its atoms.

E.Energy is the capacity to do work.

A buffer contains 0.50 mol NH4

+ and 0.50 mol NH3 diluted with water to 1.0 L. How

many moles of NaOH are required to increase the pH of the buffer to 10.00? (pKa of

NH4

+ = 9.25)

A.0.035 mol

B.0.15 mol

C.0.35 mol

D.0.41 mol

E.2.8 mol