the correct systematic (iupac) name for the molecule …web.uvic.ca/~asirk/quizzkey.pdf · the...

Quiz Results

Question 1

The correct hybridizations of the atomic orbitals on the atoms labeled 1, 2 and 3 are (respectively)?

sp2, sp2, and sp2

sp2, sp3, and sp2

sp, sp2, and sp2

sp, sp3, and sp2

sp, sp3, and sp3

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Score: 1/ 1(autograded)

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Question 2

Which one of the following derivatives of ethane has the highest boiling point?

C2Cl6

C2I6

C2Br6

C2H6

C2F6

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Question 3

The correct systematic (IUPAC) name for the molecule above is:

cis-3-pentene

trans-2-pentene

trans-2-propene

cis-2-pentene

cis-1-methyl-1-butene

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Question 4

Pentane has __________ structural isomers.

2

4

0

1

3

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Question 5

Which statement about hydrocarbons is false?

The smallest alkane to have structural (constitutional) isomers has 4 carbon atoms.

Alkanes can be produced by hydrogenating alkenes.

Cyclic alkanes are structural isomers of alkenes.

Alkenes undergo addition reactions.

Alkanes are more reactive than alkenes.

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Question 6

Which of the following compounds does not contain a C=O bond?

aldehydes

amides

ketones

esters

ethers

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Question 7

What would be the missing reagants (reaction conditions in brackets)?

H2O

H2O (H2SO4)

HBr

Cl2

H2 and (Ni, 500 degrees)

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Question 8

Which of the following is false about aromatic compounds?

They undergo electrophilic aromatic substitution reactions.

They have delocalised pi bonds across the aromatic system.

All bond lengths in benzene are the same.

They undergo addition reactions across the double bonds.

All bond strengths in graphite are the same.

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Question 9

The molecular geometry of each carbon atom in an alkane is __________.

octahedral

square planar

trigonal planar

tetrahedral

trigonal pyramidal

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Question 10

The compound above is an __________.

alkyne

alkene

alkane

aromatic compound

olefin

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Question 11

Which substance would be the most soluble in gasoline?

water

NaNO3

HCl

hexane

NaCl

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Question 12

The addition of HBr to 2-butene produces __________.

1-bromobutane

2-bromobutane

1,2-dibromobutane

2,3-dibromobutane

no reaction

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Question 13

The general formula for an ether is __________.

R-O-R'

R-CO-R'

R-CO-OH

R-OH

RCO-H

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Question 14

The general formula of an ester is __________.

R-O-R'

R-CO-O-R'

R-CO-OH

R-OH

RCO-H

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Question 15

How many isomers of C2H2Cl2 have a net dipole moment?

none

1

2

3

It is impossible to tell without more information

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Expand question feedback Quiz 2

Quiz Results

Question 1

Which of the above contains an amide linkage between R and R'?

A

B

C

D

E

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Question 2

Which of the above molecules is chiral?

A

B

C

D

E

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Question 3 How many chiral centers are there in CH3CHClCH2CH2CHBrCH3?

0

1

2

3

4

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Question 4

Which of the above could be formed by oxidation [O] of a secondary alcohol?

A

B

C

D

E

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Question 5

Which of the above is an ether?

A

B

C

D

E

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Question 6

Which two of the above could be reacted together to make an amide?

A and C

B and D

C and E

B and E

A and D

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Question 7

Which of the above can be formed by reaction of ethyl benzoate and water in the presence of an acid ?

A

B

C

D

E

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Question 8

The two compounds shown above are

optical isomers

enantiomers

diasteriomers

the same

A and B mean the same thing

B and C mean the same thing

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Question 9

What would be the best way to describe the above compounds?

They are diasteriomers with configurations R for compound A and S for compound B

They are the same compound

They are enantiomers with configurations R for compound A and S for compound B

They are optical isomers with configurations S for compound A and R for compound B

They are meso compounds

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Question 10

How would you match the 4 monomers above with the 4 resulting addition polymers?

A=1, B=2, C=3, D=4

A=2, B=3, C=1, D=4

A=3, B=1, C=4, D=2

A=3, B=2, C=4, D=1

A=4, B=2, C=3, D=1

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Question 11

Which of the five molecules is an isomer of compound 1 shown above.

A

B

C

D

E

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Question 12 What type of isomerisation was shown in the previous question

conformational

geometric

optical

structural

diastereoisomers

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Question 13

What type of alcohol is depicted?

primary alcohol

secondary alcohol

tertiary alcohol

quaternary alcohol

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Question 14 When drawing a mechanism using curved arrows to depict electron movement, the arrows will always go from

a region of high electron density to a region of low electron density.

from a positive charge to a negative charge

from a base to an acid

from the more reactive molecule to the less reactive molecule

from the reactant to the product

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Question 15 Which of the following is false about functional groups?

Carboxylic acids are rigid and planar due to the resonance contribution of double bonds to both oxygens.

Oxidation of a secondary alcohol gives a ketone.

An aldehyde can be oxidised to a carboxylic acid.

They tend to be electron poor.

The reaction of an ester to form a carboxylic acid will also produce an alcohol.

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Quiz 3

Quiz Results

Question 1 Which of the following would not affect the rate of a chemical reaction?

The temperature of the reaction.

The addition of a catalyst.

The concentration of reactants

Whether the reactants are in solid or liquid phase

The size of the erlenmeyer flask the reaction is run in.

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Question 2 What is an example of using a change in concentration to increase the rate of a reaction?

Milk spoils faster when left on the counter than when stored in the fridge.

Sulphuric acid readily dissolves a metal container that could hold acetic acid for months.

The addition of a catalytic convertor decreases the amount of CO that is in the car exhaust.

An aluminium bikeframe does not rust whereas an iron bikeframe rusts readily.

An epipen is used to inject medicine directly into the bloodstream to stave off a potentially fatal allergic reaction.

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Question 3 Consider the following reaction: 3A-->2B. The average rate of appearance of B is given by Δ [B]/Δ t. Comparing the rate of appearance of B and the rate of disappearance of A, we get Δ B/Δ t = ×(Δ [A]/Δ t

"-2/3"

"+2/3"

"-3/2"

"1"

"3/2"

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Question 4

A flask is charged with 0.124 mol of A and allowed to react to form B according to the reaction A(g) --> B(g). The above data are obtained for [A] as the reaction proceeds. These data will be used to answer this question and the next two questions. The average rate of disappearance of A between 10 s and 20 s is __________ mol/s

2.2*10-3

1.1*10-3

4.4*10-3

454

8.8*10-4

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Question 5 For the above reaction of A(g) --> B(g), what is the average rate of disapearance of A over the 40 s of the reaction?

1.75*10-3

0.054

3.1*10-3

0.124

1.35*10-3

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Question 6 For the above reaction of A(g) --> B(g), how many moles of B are present after the reaction has proceeded for 10 sec? Assume no B was initially present.

0.011

0.028

0.014

0.054

0.124

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Question 7

A flask is charged with 0.124 mol of A and allowed to react to form B according to the reaction A(g) --> 2B(g). The above data are obtained for [A] as the reaction proceeds. These data will be used to answer this question and the next question. The average rate of appearance of B between 10 s and 20 s is __________ mol/s

2.2*10-3

1.1*10-3

4.4*10-3

454

8.8*10-4

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Question 8 For the above reaction of A(g) --> 2B(g), how many moles of B are present after the reaction has proceeded for 10 sec? Assume no B was initially present

0.011

0.028

0.014

0.054

0.124

B and C

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Question 9

The peroxydisulfate ion reacts with the iodide ion in aqueous solution via the above reaction. An aqueous solution containing 0.050 M of Sand 0.072 M of I- is prepared, and the progress of the reaction followed by measuring [I- ]. The data obtained is given in the table above. This data will be used to answer this question and the next question. The average rate of disapearance of I- between 400.0 s and 800.0 s is __________ moles/s.

2.8*10-5

9.2*10-6

5.8*10-5

3.6*10^4

2.6*10-4

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Question 10 Using the reaction and data table from the previous question, the average rate of disapearance of S2O8 2- between 400.0 s and 800.0 s is __________ moles/s.

2.8*10-5

9.2*10-6

5.8*10-5

3.6*10^4

2.6*10-4

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Question 11 A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction __________ if the concentration of CO doubled, with everything else kept the same.

doubles

remains unchanged

triples

increases by a factor of 4

is reduced by a factor of 2

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Question 12 The experimentally determined rate law for the reaction 2 NO(g) +2H2(g) --> N2(g) +2 H2O is : rate= [NO]2[H2]. What are the reaction orders for this rate law?

1st order in NO, 2nd order in H2, 2nd order overall

2nd order in NO, 1st order in H2, 2nd order overall

2nd order in NO, 2nd order in H2, 3rd order overall

2nd order in NO, 1st order in H2, 3rd order overall

1st order in NO, 1nd order in H2, 2nd order overall

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Question 13 The experimentally determined rate law for the reaction 2 NO(g) +2H2(g) --> N2(g) +2 H2O is : rate= [NO]2[H2]. If the NO concentration is doubled and the H2 concentration is held the same what happens to the rate?

No change

Doubles

Triples

Increases by a factor of 4


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Question 14 The experimentally determined rate law for the reaction 2 NO(g) +2H2(g) --> N2(g) +2 H2O is : rate= [NO]2[H2]. If the H2

and the NO concentration is held the same what happens to the rate?

No change

Doubles

Triples



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Question 15 How could one increase the rate of a gas phase reaction? Assume the number of moles of initial reactants is constant and the vessel is held at a constant temperature in the absense of a catalyst and with no change in state.

Increase the size of the reaction vessel thereby increasing the pressure and increasing the reaction rate.

Decrease the size of the reaction vessel thereby increasing the pressure and increasing the reaction rate.

Increase the size of the reaction vessel thereby decreasing the pressure and increasing the reaction rate.

Decrease the size of the reaction vessel thereby decreasing the pressure and increasing the reaction rate.

There is no way to affect the rate of the reaction.

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Quiz 4

Quiz Results

Question 1

For a reaction of the type A + B + C going to products, the following observations are made:

Doubling the concentration of A doubles the rate, doubling the concentration of B has no effect on the rate, and tripling the concentration of C increases the rate by a factor of 9. What is the rate law for the reaction?

rate = k[A]2[B][C]2

rate = k[A][C]2

rate = k[A]2[B][C]

rate = k[A][B][C]

rate = k[A]2[C]

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This is the feedback text Question 2

The following data were collected for the rate of disappearance of NO in the reaction: 2NO(g) + O2 (g) --> 2NO2, What is the rate law for the reaction and the value of the rate constant?

rate = k[NO]2[O2], k = 7.11 x 103 M-2 s-1

rate = k[NO][O2]2, k = 7.16 x 103 M-2 s-1

rate = k[O2], k = 1.12 M-2 s-1

rate = k[NO]2, k = 8.88 x 101 M-1 s-1

rate = k[NO][O2], k = 8.95 x 101 M-1 s-1

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Which concentration plot is linear for a first-order equation? (A is one of the reactants.)

1/[A] versus time

square root of [A] versus time

[A]2 versus time

ln[A] versus time

[A] versus time

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In a second-order reaction the rate constant is 4.00 x 10-4 M-1 s-1. What is the concentration of reactant after 10 min if the initial concentration is 0.800 M?

0.629 M

0.300 M

0.797 M

1.49 M

0.671 M

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Question 5

The thermal decomposition of N2O5(g) to form NO2(g) and O2(g) is a first-order reaction. The rate constant for the reaction is 5.1 x 10-4 s-1 at 318 K. What is the half-life of this process?

3.9 x 103 s

2.0 x 103 s

1.4 x 103 s

2.6 x 10-4 s

1.0 x 10-3 s

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Question 6

As the temperature of a reaction in solution is increased, the rate of the reaction increases because the

reactant molecules collide less frequently.

reactant molecules collide with greater energy.

activation energy is lowered.

reactant molecules collide less frequently with a lower energy.

reactant molecules collide less frequently and with greater energy.

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Question 7

In a series of reactions, which is the rate-determining step?

the slowest reaction

the reaction with the highest order

the simplest reaction

the fastest reaction

the main reaction involving the major reactant

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Question 8

Write a rate law for the following elementary reaction: NO + Cl2 --> NOCl2 and determine the molecularity of the elementary reaction.

rate = k[NO][Cl2]2; bimolecular

rate = k[NO][Cl2]; bimolecular

rate = k[NO]2[Cl2]; termolecular

rate = k[NO][Cl2]; unimolecular

rate = k[NO][Cl2]2; termolecular

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Question 9

Which one of the following statements is incorrect?

Heterogeneous catalysts are often found on a solid in contact with gaseous reactants.

Catalysts speed up a reaction by lowering the activation energy.

An automotive catalytic converter uses a catalyst to burn gasoline better for higher gas mileage.

Homogeneous catalysts are present in the phase where the reactions take place.

Enzymes are biological catalysts.

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Question 10

The proper expression for Kc for the reaction

NiCO3(s) + 2H+(aq) --> Ni2+

(aq) + CO2(g) + H2O(l) is

[NiCO3]/[Ni2+].

[CO2]

[Ni2+]/[H+]2

[Ni2+]/[NiCO3]

[Ni2+][CO2]/[H+]2.

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Question 11

Calculate the equilibrium constant for the reaction: 2SO3(g) --> 2SO2(g) + O2(g) if a 3.25-L tank is found to contain 0.343 atm O2, 0.0212 atm SO3, and 0.00419 atm SO2 at equilibrium.

6.79 x 10-3

4.12 x 10-3

2.43 x 102

1.34 x 10-2

8.78

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Question 12

In which of the following elementary processes is the molecularity unimolecular?

(i) N2O(g) + Cl(g) --> N2(g) + ClO(g)

(ii) Cl2(g) --> 2Cl(g)

(iii) NO(g) + Cl2(g)--> NOCl2(g)

i only

ii and iii only

i and iii only

iii only

ii only

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Question 13

The following mechanism has been proposed for the reaction of NO with H2:

NO + NO --> N2O2

N2O2 + H2 --> N2O + H2O.

If the observed rate law is rate = k[NO]2[H2], what can be concluded about the relative speeds of the first and second steps?

The first step is slower than the second step.

The first step is faster than the second step.

The rates are about the same.

Nothing can be determined.

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Question 14

Given the following mechanism for the formation of XO2, which species is a catalyst?

X + YO2 --> XO + YO

XO + YO2 --> XO2 + YO

YO + O2 --> YO2 + O

YO + O --> YO2

XO

XO2

X

YO2

O2

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Question 15

Given the following mechanism, what is the overall balanced equation?

X + YO2 --> XO + YO

XO + YO2 --> XO2 + YO

YO + O2 --> YO2 + O

YO + O --> YO2

X+YO --> YO +XO

YO + O --> YO2

X+O2-->XO2

2X+2YO2 +O2 -->2YO +2XO2

X + 2YO + 2O2 --> 2YO2 +XO2

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Expand question feedback Quiz 5

Quiz Results

Question 1

A flask is charged with 0.124 mol of A and allowed to react to form B according to the reaction 2A(g) --> 3B(g). The above data are obtained for [A] as the reaction proceeds. The average rate of appearance of B between 20 s and 30 s is __________ mol/s

0.015 Ms-1

0.030 Ms-1

0.045 Ms-1

0.0225 Ms-1

"-0.015 Ms-1"

"-0.030 Ms-1"

"-0.045 Ms-1"

"-0.0225 Ms-1"

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Consider the stoichiometry Question 2

From the following graph, calculate the average rate of reaction between t=0 and 300 seconds and the instanteous rate at t=0 seconds.

1.83E-4, 3.0E-4

1.83E-4, 1.65E-4

1.83E-4, 2.0E-4

1.50E-4, 3.0E-4

1.5E-4, 2.0E-4

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For a first order reaction 3A --> B, the initial concentration of A was 6.00 M. After 400 s, the concentration of B was 1.25 M. What is the value of the rate constant (in s-1)?

1.53E-03

9.38E-03

1.18E-03

3.92E-03

3.13E-03

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For this question, please write the integrated rate laws and sketch the graphs that give a straight line with a slope of k or -k for a zeroth, first, second reaction. Try to do this without using your notes. Then match the following values to their descriptions.

__4__ 1/[A]o

__2__ ln [A]

__6__ k

__1__ [A]

__3__ time

__5__ "-k"

1. y axis of zeroth order graph

2. y axis of first order graph

3. x axis of second order graph

4. y intercept of second order graph

5. slope of first order graph

6. slope of second order graph

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For the hypothetical gas-phase reaction 3A(g) --> 2B(g), the number of moles of A present at 25 min is found to be 0.022. If the initial number of moles of A and B were 0.050 mol and 0.00 mol, respectively, how much B is present at 25 min?

0.056 mol

0.019 mol

0.022 mol

0.028 mol

0.0093 mol

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Question 6

Consider the combustion of hydrogen: 2H2(g) + O2(g) --> 2 H2O. If hydrogen is burning at the rate of 4.6 mol s-1, what are the rates of consumption of oxygen and formation of water vapour?

4.6 mol s-1 (O2) and 4.6 mol s-1 (H2O)

-4.6 mol s-1 (O2) and +4.6 mol s-1 (H2O)

"-2.3 mol s-1 (O2) and 2.3 mol s-1 (H2O)"

-2.3 mol s-1 (O2) and -4.6 mol s-1 (H2O)

2.3 mol s-1 (O2) and 4.6 mol s-1 (H2O)

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This question tests the stoichiometry of reactions and relative rates. For additional information read pages 450

If the reaction 2A + 3D products is first-order in A and second-order in D, then the rate law will have the form:

k[A]2[D]2

k[A]2[D]

k[A]2[D]3

k[A][D]2

k[A][D]

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Section 12.3 of the textbook covers reactions orders. Sample exercise 12.6 is also very useful for determining reaction orders from the raw data. Question 8

The proper expression for Kc for the reaction

2HF(aq) + C2O42-

(aq) --> 2F-(aq) + H2C2O4(aq) is

[HF]2 [C2O4

2-] / [F-]2[H2C2O4]

2[HF] [C2O4

2-] /2 [F-][H2C2O4]

2 [F-][H2C2O4]/2[HF] [C2O4

2-]

[F-]2[H2C2O4]/[HF]2 [C2O4

2-]

[F-][H2C2O4]/[HF] [C2O4

2-]

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See section 13.2 and section 13.3. Question 13.12 has some examples (but also includes heterogeneous equilibria which is section 13.4 and not on the midterm) Question 9

Calculate the equilibrium constant for the reaction: 2SO3(g) --> 2SO2(g) + O2(g) if a 3.25-L tank is found to contain 0.343 atm O2, 0.0212 atm SO3, and 0.00419 atm SO2 at equilibrium.

6.79 x 10-3

4.12 x 10-3

2.43 x 102

1.34 x 10-2

8.78

Save Time: 10:09 PM



question feedback has been set Quiz 6

Quiz Results

Question 1 Which of the following quantities: heat, work, enthalpy, internal energy are state functions,( that is they depend only on the end points and not on the path followed in a process)?

enthalpy and internal energy

enthalpy

heat

work

internal energy

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Question 2

For a process in which the internal energy (U) does not change , which of the following are possible? (i) heat > 0, work < 0 (ii) heat > 0, work > 0 , (iii) heat < 0, work < 0 , (iv) heat < 0, work > 0

i and ii

i and iv

ii and iii

ii and iv

iii and iv

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Question 3

When 0.430 mol NH3 is formed from nitrogen and hydrogen, 18.38 kJ of energy is released as heat. Assuming constant pressure is maintained, what is the H for this reaction per mole of NH3 formed?

42.7 kJ

"-42.7 kJ"

18.4 kJ

0.024 kJ

"-0.024kJ"

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Question 4

Consider the following reaction: 2C2H2(g) + 5O2(g) 4CO2(g) + 2H2O(g) H = -2511 kJ Calculate the amount of heat transferred when 2.60 g of C2H2(g) is consumed in this reaction at constant pressure.

-6.53 x 103 kJ

-502 kJ

"-126 kJ"

-3.26 x 103 kJ

-251 kJ

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Question 5

When heat is absorbed by the system from the surroundings, the process is said to be ____________, and the sign of q is ___________.

exothermic, positive

exothermic, negative

endothermic, negative

endothermic, positive

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Question 6

An endothermic reaction is carried out in a coffee-cup calorimeter. Which statement is incorrect for this process?

The temperature of the water decreases

The products have higher enthalpy than the reactants

Heat is absorbed from the water.

The enthalpy change for the reaction is positive.

The enthalpy change for the reaction is equal to qH2O

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Question 7

The fuel used in spacecraft must contain as much energy per gram of material as possible. Based on this consideration only, which of the following fuels is best suited to be a spacecraft fuel?

(i) dimethylhydrazine, (CH3)2NNH2 H combustion = -1694 kJ/mol

(ii) methanol, CH3OH Hcombustion = -726 kJ/mol

(iii) ethanol, C2H5OH Hcombustion = -1371 kJ/mol

(iv) octane, C8H18 Hcombustion = -5500 kJ/mol

(v) ethylene glycol, C2H6O2 Hcombustion = -1190 kJ/mol

octane

ethanol

ethylene glycol

dimethylhydrazine

methanol

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Question 8

Calculate the change in internal energy (delta U) for a system undergoing an endothermic process in which 15.6 kJ of heat flows and where 1.4 kJ of work is done on the system.

17 kJ

"-17 kJ"

14.2 kJ

"-14.2 kJ"

15.6 kJ

"-15.6 kJ"

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Question 9

Calculate the work done with the expansion of gas from 46 m3 to 64 m3 at a constant external pressure of 15 Pa.

960

690

"-960"

270 J

"-270 J"

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Question 10

When 1.00 L of 1.00 M Ba(NO3)2 solution at 25 C is added to 1.00 L of 1.00 M Na2SO4 solution at 25 C in a calorimter, the white solid BaSO4 forms and the temperature of the mixture increses to 28.1 C. Assuming the calorimeter absorbs only a negligable quantity of heat, that the specific heat capacity of the solution is 4.18 J/gK and the density of the final solution is 1.0 g/mL, calculate the enthalpy change per mole of BaSO4 formed.

"-260 kJ/mol"

"-26, 000 kJ/mol"

"-26 kJ/mol"

"130 kJ/mol"

"13 kJ/mol"

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Question 11

Which of the following is not a way of stating the first law of thermodynamics.

The energy of the universe is constant.

If heat is lost by the system, it must be gained by the surroundings

Energy cannot be created or destroyed, it can only change its form.

If work is done on the system during an exothermic reaction then the energy of the system must increase.

Energy lost by the surroundings must be gained by the system

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Question 12

Choose the scenario where q<0, w>0 and delta U is <0

A reaction attached to a piston pushes up on the piston and moves it for 70 kJ of work and the system cools down absorbing 30 kJ of heat from its surroundings.

A reaction attached to a piston pushes up on the piston and moves it for 14 kJ of work and the system releases 30 kJ of heat to the surroundings.

A piston pushes down on a reaction decreasing the volume inside the reaction vessel for 15 kJ of work and 10 kJ of heat is released by the system.


A battery is attached to a reaction vessel and does electrical work (10 kJ) on the system which then undergoes a 50 kJ exothermic reaction.

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Question 13

Why is the q of an exothermic reaction considered to be negative when so much heat is released?

Because we calculate the energy of the reaction from the point of view of the system not the surroundings.




The fact that we calculate the energy of reactions in thermodynamic questions from the point of view of the system, not the surroundings may be an important concept. When a reaction explodes, consider what happens to the system, not your own eyebrows.

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Question 14

What is the kinetic energy of 0.33 moles of H2 molecules moving with an average speed of 4000 km/hr?

733 J

814 kJ

407 J

814 J

3200 kJ

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Question 15

Given the thermochemical equation 2NO(g) + O2(g) 2NO2(g) H = -114.0 kJ, calculate H for the following reaction: NO2(g) NO(g) + 1/2O2(g). Is it exothermic or endothermic?

114 kJ, exothermic

"-114 kJ", exothermic

"-114 kJ", endothermic

57 kJ, endothermic

57 kJ exothermic

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Quiz 7

Quiz Results

Question 1 Determine the value of H° in kJ for the following reaction: 2SO2(g) + O2(g) --> 2SO3(g)

"-198 kJ"

198 kJ

99 kJ

"-99 kJ"

"-357"

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Use the following thermochemical equations

C2H5OH(l) + 3O2(g) --> 2CO2(g) + 3H2O(l) H= -1367 kJ

H2(g) + 1/2O2(g) --> H2O(l) H = -286 kJ

C(graphite) + O2(g) --> CO2(g) H= -394 kJ

to calculate the standard enthalpy of formation for the following reaction:

2C(g) + 3H2(g) + 1/2O2(g) --> C2H5OH(l)

+279 kJ/mol

+687 kJ/mol

+680 kJ/mol

-279 kJ/mol

+2047 kJ/mol

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Which of these samples of gas has the highest entropy?

2 mol of methane gas occupying 2 L

1 mol of methane gas occupying 1 L

Each of these samples has the same amount of entropy because they are at the same pressure.

1 mol of ethane gas occupying 1 L

2 mol of ethane gas occupying 2 L

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Calculate The delta H for the syntheis of diborane (B2H6) from its elements using the following data:

2B(s) + 3/2O2(g) --> B2O3(s) -1273 kJ

B2H6(g) +3O2(g) -->B2O3(s) + 3H2O(g) -2035 kJ

H2(g) +1/2O2(g) --> H2O(l) -286 kJ

H2O(l) --> H2O(g) 44 kJ.

36 kJ

14 kJ

378 kJ

-378 kJ

760 kJ

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Question 5

Considering the equation ΔG = ΔH -TΔS, in which scenario MUST the reaction be spontaneous? All scenarios describe only the system.

Entropy decreases and enthalpy increases

Entropy increases and enthalpy increases

Entropy increases and enthalpy decreases

Entropy decreases and enthalpy decreases

Entropy and Enthalpy remain constant

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Question 6

Which of the following is NOT true about a spontaneous process?

The free energy of the reaction is less than zero

The entropy of the universe increaeses

The reaction is exothermic

The reverse reaction is always non spontaneous under the same reaction conditions

Whether a reaction is spontaneous can be changed by altering reaction conditions.

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Question 7

In the metallurgy of antimony, the pure metal is recovered via different reactions, depending on the composition of the ore.

For example, iron is used to reduce antimony in sulphide ores:

Sb2S3(s) +Fe(s) --> 2 Sb(s) +3FeS(s) Δ H = -125 kJ, What is the Δ S(surroundings) for this reaction at 25° C and 1 atm?

419 J/K

"-419 J/K"

5 J/K

"-5 J/K"

125 kJ

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Question 8

In the metallurgy of antimony, the pure metal is recovered via different reactions, depending on the composition of the ore.

For example, carbon is used to reduce antimony in oxide ores:

Sb4O6(s) +6C(s) --> 4Sb(s) +CO(g) Δ H = 778 kJ What is the Δ S(surroundings) for this reaction at 25 °C and 1 atm?

31.2 kJ/K

-31.2 kJ/K

-778 kJ

-2.61 kJ/K

2.61 kJ/K

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Question 9

Methanol is a fuel used in racing car engines and fuel cells. Calculate Δ G for the reaction

2CH3OH(l) + 3O2(g) --> 2CO2 (g) + 4H2O(g)

using the following free energies of formation :

CH3OH(l) -163 kJ/mol

CO2 (g) -394 kJ/mol

O2(g) 0 kJ/mol

H2O(g) -229 kJ/mol.

-1378 kJ

- 460kJ

-1500 kJ

-765 kJ

-980 kJ

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Question 10

In which case does the entropy of the system decrease significantly?

C(s) + O2(g) --> CO2(g)

N2(g) + 3H2(g) --> 2NH3(g)

CaCO3(s) --> CaO(s) + CO2(g)

H2O(l) --> H2O(g)

SnO2(s) + 4C(s) --> Sn(s) + 4CO2(g)

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Question 11

Some standard entropies (at 25°C in J/mol K) are given in the following list: diamond 2.43, O2(g) 205.0, CO(g) 197.9. The value of S° for the reaction: 2C(diamond) + O2(g) --> 2CO(g) at 25°C in J/K is

-9.5 J K-1

390.9 J K-1

-185.9 J K-1

+185.9 J K-1

+9.5 J K-1

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Question 12

Calculate G° in kJ at 350°C for the reaction: 2NO2(g) --> N2O4(g)

For NO2(g) Hf° = 33.18 kJ/mol and S°= 240.1 J/molK For N2O4(g) Hf° = 9.16 kJ/mol and S° = 304.3 J/molK

-413 kJ

-64.0 kJ

52.4 kJ

4.37 kJ

1.10 x 105 kJ

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Question 13

Calculate S in J/K for the reaction: C(s) + O2(g) --> CO2(g)

S° J/molK = 5.69 for C(s), 205 for O2(g) and 213.6 for CO2(g)

-424.3 J/K

424.3 J/K

2.9 J/K

-2.9 J/K

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Question 14

Choose the scenario where q>0, w<0 and ΔU <0

A reaction attached to a piston pushes up on the piston and moves it for 70 kJ of work and the system cools down absorbing 30 kJ of heat from its surroundings

A reaction attached to a piston pushes up on the piston and moves it for 14 kJ of work and the system releases 30 kJ of heat to the surroundings.

A piston pushes down on a reaction decreasing the volume inside the reaction vessel for 15 kJ of work and 10 kJ of heat is released by the system


A battery is attached to a reaction vessel and does electrical work (10 kJ) on the system which then undergoes a 50 kJ exothermic reaction.

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Question 15

Which of the following processes are spontaneous and which are nonspontaneous: (i) separation of gaseous N2 and O2 molecules from each other, (ii) the reaction of sodium metal with chlorine gas to form sodium chloride, (iii) the dissolution of HCl(g) in water to form concentrated hydrochloric acid?

(i) nonspontaneous (ii) spontaneous , (iii) spontaneous

(i) nonspontaneous (ii) nonspontaneous , (iii) spontaneous

(i) spontaneous (ii) spontaneous , (iii) spontaneous

(i) nonspontaneous (ii) spontaneous , (iii) nonspontaneous

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Quiz 8

Quiz Results

Question 1 Designate the conjugate Br�nsted-Lowry acid for each of the following bases: (i) NH3 (ii) CN- (iii) NH2-

NH4+, H2CN, NH3

NH4+, HCN, NH3

NH3, H2CN, NH3

NH2-, HCN, NH4+

NH3, HCN, NH3

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What is the concentration of hydronium ions in a solution with a hydroxide-ion concentration of 2.31 x 10-4 M at 25�C?

4.33 x 10-11 M

2.31 x 10-4 M

2.31 x 10-18 M

2.31 x 1010 M

1.8 M

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Calculate the pH of a solution if its [OH-] = 0.0000700 M and indicate whether the solution is acidic, basic, or neutral.

9.8, acidic

11, basic

2.15, acidic

9.8, basic

17.2, basic

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Which one of the following 0.1 M solutions would have a pH of 7.0?

NH4Cl

Cu(CH3COO)2

NaF

NaNO3

Na2S

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Question 5

If the pH of a solution is 6.30, what are the molar concentrations of H+(aq) and OH-(aq) at 25�C?

5.0 x 10-7 M and 1.0 x 10-7 M

1 x 10-7 M and 6.3 x 10-7 M

5.0 x 10-7 M and 5.0 x 10-7 M

6.3 x 10-7 M and 1.0 x 10-7 M

5.0 x 10-7 M and 2.0 x 10-8 M

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Question 6

Which of the following acids, if in solutions of equal concentration, is the most acidic?

boric acid, Ka = 5.8 x 10-10

HF, Ka = 6.3 x 10-4

lactic acid, Ka = 1.4 x 10-4

acetic acid, Ka = 1.8 x 10-5

All of these acids are equally acidic because they are all of equal concentration.

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Question 7

Lactic acid, HC3H5O3, has one acidic hydrogen. A 0.10 M solution of lactic acid is measured with a pH of 2.44. Calculate Ka based on this data.

3.6 x 10-3

1.3 x 10-4

1.3 x 10-5

1.4 x 10-4

1.0 x 10-3

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Question 8

Calculate the pH of the following strong acid solution: 2.02 g of HNO3 in 400 mL of solution

4

1.7

2.3

1.5

1.1

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Question 9

Which of the following statements is false?

A Lewis acid does not have to contain a proton.

An Arrhenius acid is a proton acceptor

Metal ions show acidic properties.

A Lewis base is an electron pair donor.

Salts dissolve in water due to the attraction of the positive ions for water molecules.

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Question 10

Given the following Ka values, HC2H3O2 Ka = 1.8 x 10-5 HClO3 Ka = 5.0 x 10^2 HCN Ka = 4.9 x 10-10 HF Ka = 6.8 x 10-4 HOCl Ka = 3.0 x 10-8 Which is the weakest base?

CN-

ClO3-

OCl-

C2H3O2-

F-

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the correct systematic (iupac) name for the molecule …web.uvic.ca/~asirk/quizzkey.pdf · the...

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