Chem 89646 | Course Paper

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Which molecule in the reaction below is the oxidizing agent?

2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O(g)

A.C2H6

B.O2

C.H2O

D.CO2

E.None

What is the pH of a buffer that results when 0.50 mole of H3PO4 is mixed with 0.25

mole of NaOH and diluted with water to 1.00 L? (The acid dissociation constants of

phosphoric acid are Ka1 = 7.5 10“3, Ka2 = 6.2 10“8, and Ka3 = 3.6 10“13)

A.1.82

B.2.12

C.6.91

D.7.21

E.12.44

Sulfur trioxide reacts with water to produce sulfuric acid. What change in hybridization

of the sulfur atom occurs in this reaction?

A.sp3 to sp2

B.sp3 to sp

C.sp2 to sp3

D.sp2 to sp3d2

E.no change

What volume of Ar at 45 C and 1.25 atm contains the same number of particles as 0.655

L of H2 at 15 C and 2.00 atm?

A.0.452 L

B.1.16 L

C.0.949 L

D.0.371 L

E.3.14 L

Determine the equilibrium constant for the following reaction

Mg(OH)2(s) + 2 H+(aq) Mg2+(aq) + 2 H2O( )

given the chemical reactions below.

Mg(OH)2(s) Mg2+(aq) + 2 OH“(aq) K = 5.6 10“12

H2O( ) H+(aq) + OH“(aq) K = 1.0 10“14

A.1.1 10“25

B.5.6 10“12

C.5.6 102

D.1.1 103

E.5.6 1016

Which of the following colors of visible light has the lowest frequency?

A.green

B.orange

C.red

D.yellow

E.blue

What is the binding energy of an electron in a photosensitive metal (in kJ/mol) if the

longest wavelength of light that can eject electrons from the metal is 198 nm?

A.279 kJ/mol

B.604 kJ/mol

C.792 kJ/mol

D.1.51 1012 kJ/mol

E.6.04 10“20 kJ/mol

The point of maximum stability in the binding energy curve occurs in the vicinity of

which one of the following isotopes?

Which of the following statements is/are CORRECT?

1/ Spontaneous changes only occur in the direction that leads to equilibrium.

2/ Exothermic reactions are always spontaneous.

3/ In any chemical reaction, energy must be conserved.

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2, and 3

Heat capacity is defined as

A.the amount of heat required to raise the temperature of 1 gram of substance by 1 K.

B.the amount of heat required to raise the temperature of a substance by 1 K.

C.the amount of heat required to vaporize a solid or liquid.

D.the maximum amount of heat that a substance may absorb without decomposing.

E.4.18 cal/gK.

If 35.0 g H2O at 22.7 C is combined with 65.0 g H2O at 87.5 C, what is the final

temperature of the mixture? The specific heat capacity of water is 4.184 J/gK.

A.25.1 C

B.45.4 C

C.50.8 C

D.64.8 C

E.48.9 C

Al3+ is reduced to Al(s) at an electrode. If a current of 2.75 ampere is passed for 36

hours, what mass of aluminum is deposited at the electrode? Assume 100% current

efficiency.

A.9.2 10“3 g

B.3.3 101 g

C.9.9 101 g

D.1.0 102 g

E.3.0 102 g

Which of the following atoms contains the fewest protons?

A.232Th

B.231Pa

C.245Pu

D.238U

E.232Pa

Which of the following compounds may have linkage isomers?

A.[Ni(H2O)4Cl2]Cl

B.[Ni(NH3)4Cl2]NO2

C.[Ni(H2O)5(SCN)]SO4

D.[Ni(H2O)5Cl](SCN)2

E.[Ni(NH3)4Cl2]Cl

If 3.01 g of water is sealed in an evacuated 2.00 L flask and heated to the normal

boiling point of 373 K, what is the pressure in the flask? (R = 0.08206 Latm/molK)

A.0.391 atm

B.0.678 atm

C.1.00 atm

D.2.56 atm

E.46.1 atm

Diagram 9-1

The molecular orbital diagram below may be used for the following problem(s). For

oxygen and fluorine, the s2p orbital should be lower in energy than the p2p. However,

the diagram will still yield correct bond order and magnetic behavior for these

molecules.

Energy ________ s*2p

________ ________ p*2p

________ s2p

________ ________ p2p

________ s*2s

________ s2s

________ s*1s

________ s1s

Refer to Diagram 9-1. Use molecular orbital theory to predict which species is

paramagnetic.

A.N2

B.B2

C.F2

D.Li2

E.H2

A sealed tube is prepared with 1.66 atm PCl5 at 500 K. The PCl5 decomposes until

equilibrium is established.

PCl5(g) PCl3(aq) + Cl2(g)

The equilibrium pressure in the tube is 2.28 atm. Calculate Kp.

A.0.17

B.0.23

C.0.37

D.0.62

E.4.3

If 50.0 g of benzene, C6H6, at 25.0 C absorbs 2.71 kJ of energy in the form of heat,

what is the final temperature of the benzene? The specific heat capacity of benzene is

1.72 J/gK.

A.25.0 C

B.31.5 C

C.56.5 C

D.32.3 C

E.57.3 C

Calculate the standard entropy change for the combustion of ethanol at 25 C.

CH3CH2OH( ) + 3 O2(g) 2 CO2(g) + 3 H2O(g)

Species S (J/Kmol)

CH3CH2OH( ) 160.7

O2(g) 205.1

CO2(g) 213.7

H2O(g) 188.8

A.”35.9 J/K

B.+35.9 J/K

C.+217.8 J/K

D.+422.9 J/K

E.+833.1 J/K

Which of the following molecules or ions is the strongest acid?

A.CH3CO2

“

B.CH3CO2H

C.CFH2CO2H

D.CF2HCO2H

E.CF3CO2H

The wavelength of light emitted from a particular red diode laser is 651 nm. What is the

wavelength in meters?

A.6.51 1011 m

B.6.51 10“2 m

C.6.51 10“4 m

D.6.51 10“7 m

E.6.51 10“9 m

What is the atomic symbol for an element with 39 protons and 50 neutrons?

Given the following chemical equilibrium,

COCl2(g) CO(g) + Cl2(g)

calculate the value of Kc, given that Kp = 6.5 1011 at 298 K. (R = 0.08206 Latm/molK)

A.1.5 10“12

B.3.8 10“11

C.1.1 109

D.2.7 1010

E.1.6 1013

Rank the subatomic particles from least to greatest mass.

A.electron mass = proton mass = neutron mass

B.electron mass = neutron mass < proton mass

C.electron mass = proton mass < neutron mass

D.electron mass < proton mass < neutron mass

E.electron mass < proton mass = neutron mass

Determine the standard enthalpy of formation of Fe2O3(s) given the thermochemical

equations below.

Fe(s) + 3 H2O( ) Fe(OH)3(s) + 3/2 H2(g) DrH = +160.9 kJ/mol-rxn

H2(g) + 1/2 O2(g) H2O( ) DrH = “285.8 kJ/mol-rxn

Fe2O3(s) + 3 H2O( ) 2 Fe(OH)3(s) DrH = +288.6 kJ/mol-rxn

A.”252.6 kJ/mol-rxn

B.+163.7 kJ/mol-rxn

C.”824.2 kJ/mol-rxn

D.+33.2 kJ/mol-rxn

E.+ 890.6 kJ/mol-rxn

What is the mass percent of each element in sulfuric acid, H2SO4?

A.2.055% H, 32.69% S, 65.25% O

B.1.028% H, 32.69% S, 66.28% O

C.28.57% H, 14.29% S, 57.17% O

D.1.028% H, 33.72% S, 65.25% O

E.2.016% H, 32.07% S, 65.91% O

How many alcohols have the formula C4H10O?

A.2

B.3

C.4

D.5

E.6

Which element has the ground state electron configuration [Ar]3d104s1?

A.Cu

B.Zn

C.Ge

D.Ag

E.Cd

Calculate for the reaction below,

5 Cd(s) + 2 MnO4

“(aq) + 16 H+(aq) 5 Cd2+(aq) + 2 Mn2+(aq) + 8 H2O( )

given the following standard reduction potentials.

MnO4

“(aq) + 8 H+(aq) + 5 e“ Mn2+(aq) + 4 H2O( ) E = +1.52 V

Cd2+(aq) + 2 e“ Cd(s) E = “0.40 V

A.”1.12 V

B.+1.04 V

C.+1.92V

D.+5.04 V

E.+8.40 V

Which of the following are resonance structures for formate ion, HCO2

“?

A.1 and 2

B.2 and 3

C.3 and 4

D.1, 3, and 4

E.2, 3, and 4

Buckminsterfullerene is a molecule composed of sixty ________ atoms.

Concentrated nitric acid reacts with copper to form NO2(g). Dilute nitric acid reacts

with copper to form NO(g). Why does the reaction involving the dilute acid give a

different nitrogen oxide than the concentrated acid?

Use the standard entropies for liquid water and steam to estimate the enthalpy of

vaporization of water at its normal boiling point. DS [H2O( )] = 69.9 J/Kmol and DS

[H2O(g)] = 188.8 J/Kmol.

The molecular geometry of a molecule whose central atom has four single bonds and

one lone pair of electrons is ________.

The change in entropy for any process is not dependent upon the pathway by which the

process occurs. In other words, the change in entropy for any process is a(n) ________

function.

A solution is a homogeneous mixture composed of one or more ____________

dissolved in a solvent.

The numbers preceding the formulas in chemical equations are referred to as the

________ coefficients.

Does the formation of complex molecules such as proteins and nucleic acids from more

simple molecules contradict the second law of thermodynamics?

The rate of effusion of a gas is inversely proportional to the square root of its ________.

The process by which long chain hydrocarbons in petroleum are shortened is called

________.

Explain the difference between paramagnetic and ferromagnetic.

Robert Boyle observed that the volume of a fixed amount of gas is inversely

proportional to its ________.

Which of the following statements is/are CORRECT?

A joule is defined as the energy required to change 1.00 g of water from 14.5 C to 15.5

One calorie (c) equals 4.184 J, where the joule (J) is the SI unit of energy.

A calorie (c) is equal to 1000 dietary calories (C).

A.1 only

B.2 only

C.3 only

D.1 and 2

E.1, 2, and 3

In an electrolytic cell, reduction occurs at the ________ and oxidation occurs at the

________.

For a monoprotic acid titration, the ________ point in a titration is the point where the

moles of strong base added equals the moles of acid initially present.

What are the names of four metalloids?

In vulcanized rubber, the polymer chains of natural rubber are cross-linked with sulfur

atoms. The polymer chains stretch when stressed, but they return to their original shape

when the stress is removed. Substances that behave this way are called ________.

The pH of purified water (or of a neutral solution) is _____.

The hybridization of the xenon atom in XeOF4 is ________.