A Multiple choice questions B Short answer questions 8 8 ... · PDF fileWhich of the following statements regarding ... The EMF of a cell ... • Make sure that all chemical equations

Reading Time: 15 minutes

Writing Time: 1 hour 30 minutes

Structure of Book

Section

Number of Questions

Number of Questions to be

Answered

Number of

Marks

Suggested Times (min)

A

Multiple choice questions

20 20 20 28

B Short answer questions 8 8 45 62

Total 65 Total 90

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The School For Excellence 2017 Unit 3 Chemistry – Energy – Test 1 Page 1

Specific Instructions For Section A Section A consists of 20 multiple-choice questions. Section A is worth approximately 31% of the marks available. You should spend approximately 28 minutes on this section. Choose the response that is correct or best answers the question, and shade the square on the multiple-choice answer sheet according to the instructions on that sheet. A correct answer is worth 1 mark, an incorrect answer is worth no marks. No mark will be given if more than one answer is shown for any question. Marks will not be deducted for incorrect answers. You should attempt every question.

QUESTION 1 Which of the following statements regarding biodiesel is incorrect? A Biodiesel is derived from a renewable resource.

B Biodiesel creates higher sulfur emissions than diesel when it is burned.

C Biodiesel breaks down more quickly than diesel in the environment,

D Unlike fossil fuels such as gasoline, biodiesel does not cause an overall increase in the amount of CO2 in the atmosphere when the fuel is burned. QUESTION 2

In which order does the energy content in /kJ g of the given fuels increase?

A Natural gas Petroleum Coal B Natural gas Coal Petroleum C Petroleum Natural gas Coal D Coal Petroleum Natural gas QUESTION 3

In which order does the amount of carbon dioxide produced (3/10mol kJ ) increase during

combustion? A Natural gas Petroleum Coal B Natural gas Coal Petroleum C Petroleum Natural gas Coal D Coal Petroleum Natural gas


QUESTION 4

The specific heat capacities of ethanol and water are 114.2 CJg o and

112.4 CJg o

respectively. This means that A It takes more energy to heat water, and water will stay hot for longer. B It takes more energy to heat water, and ethanol will stay hot for longer. C It takes more energy to heat ethanol, and water will stay hot for longer. D It takes more energy to heat ethanol, and ethanol will stay hot for longer. QUESTION 5

The specific heat capacity of water is 1118.4 CJg o. The energy in kJ required to boil

exactly L500.0 of water at Co7.20 is

A kJ166.0

B kJ05.1

C kJ166

D kJ209

QUESTION 6

The molar heat capacity of sulfuric acid is 11139 molJK . What is the specific heat capacity

of sulfuric acid, measured in 11 CJg o?

A 11705.0 CJg o

B 1142.1 CJg o

C 119.49 CJg o

D 11387 CJg o

QUESTION 7 Galvanic cells consist of two half cells, an external circuit and an internal circuit. Which of the following statements regarding galvanic cells is true? A Electrons flow towards the cathode and cations migrate towards the cathode. B Electrons flow towards the cathode and cations migrate towards the anode. C Electrons flow towards the anode and cations migrate towards the cathode. D Electrons flow towards the anode and cations migrate towards the anode.


QUESTION 8 A galvanic cell was constructed using the following equipment.

• M1 solutions of magnesium nitrate and zinc nitrate.

• Small rods of magnesium and zinc.

• Connecting wires and a salt bridge. The reaction occurring at the cathode was:

A eMgMg aqs 22

B saq MgeMg 22

C eZnZn aqs 22

D saq ZneZn 22

QUESTION 9 Two half cells were connected to convert chemical energy into electrical energy as follows:

The overall cell reaction is:

A saqaqs SnAgSnAg 2

B saqaqs SnAgSnAg 22 2

C aqssaq SnAgSnAg 2

D aqssaq SnAgSnAg 222

Tin

Ag+(aq) Sn2+ (aq)

V

Silver


QUESTION 10 The following galvanic cell was set up in a laboratory. After a period of time, both of the electrodes were carefully removed, washed and dried. The mass of the tin electrode would have: A Increased as the tin metal was oxidised. B Increased as the tin ions were reduced. C Decreased as the tin metal was oxidised. D Decreased as the tin ions were reduced. QUESTION 11

The EMF of a cell constructed using the standard NiNi /2 and

24 / SnSn half cells would

be: A 0.38 V, with the Ni electrode positive. B 0.38 V with the Pt electrode positive. C 0.18 V, with the Ni electrode positive. D 0.18 V, with the Pt electrode positive. QUESTION 12 In commercial galvanic cells, a separator is used instead of a salt bridge. Which of the following is NOT a property that the separator should possess? A Good conductor of electricity B Will allow certain ions to migrate through it C Inert D Low density

QUESTION 13 Galvanic cells and electrolytic cells have several features in common. Which of the following is not common to both galvanic and electrolytic cells? A An electrolyte is required between the two electrodes. B Oxidation occurs at the anode. C Oxidation is loss of electrons and therefore the anode is negative. D Cations migrate to the cathode.

NiSO4 (aq) SnSO4 (aq)

V

Ni (s) Sn (s)


Pb

Electrode 2

QUESTION 14

Consider the following electrolytic cell where 2B represents a metal ion.

Sufficient charge was passed through the cell to cause metal B to be deposited on one of the electrodes.

Which of the following statements is correct? A Electrode 1 represents the anode.

B Metal B would be deposited at electrode 1. C Electrons flow through the electrolyte from electrode 1 to 2.

D ][ )(

aqB will decrease during the electrolytic process.

QUESTION 15 Consider the following electrolytic cell. The reaction that occurs at the anode is

A ePbPb aqs 22

)()(

B eAgAg aqs )()(

C eHOOH aqgl 442 )()(2)(2

D )()(2)(2 222 aqgl OHHeOH

QUESTION 16 Which one of the following salts would give the same products irrespective of whether the

molten salt or a M1 solution is electrolysed.

A Magnesium bromide B Magnesium sulphate C Copper bromide D Copper sulphate

+ -

Ag

KBr(aq)

)(aqB

B B

- +

Electrode 1


QUESTION 17 A student had three beakers labelled A, B and C. Into each of the beakers he put a different solution and two carbon rods. The three solutions he used were silver chloride, copper (II) chloride and chromium (III) chloride. After the solutions had been electrolysed for a short time, and some calculations were completed, the following graph was drawn. The solution in beaker C is A Silver chloride B Copper (II) chloride C Chromium (III) chloride D Cannot be determined QUESTION 18 The number of Faradays of electricity required to produce 1 mole of copper metal from copper (II) ions is A One B Two C 1 x 96500 D 2 x 96500 QUESTION 19 Several metals are produced by the electrolysis of molten salts. In one such case a current

of A000,30 produced kg4.22 of metal per hour. Given that the cation of the metal has a

valency of 2 , the metal being produced is A Calcium B Bromine C Magnesium D Sodium

Number of Coulombs Passed

100000 200000 300000

0.25

Number of Mole of Metal Deposited

Beaker A

Beaker B

Beaker C

0.50

0.75

1.00


QUESTION 20 Two electrolytic cells were connected in series as shown.

The electrolytes are M0.1 solutions of copper (II) sulphate and magnesium sulphate, and

the electrodes are all graphite rods. The equations for the cathode reactions of Cell A and Cell B are, respectively: Cell A Cell B

A saq CueCu 22

)( saq MgeMg 22

)(

B saq CueCu 22

)( gaql HOHeOH 2)(2 222

C eHOOH aqgl 442 )(22 gaql HOHeOH 2)(2 222

D saq CueCu 22

)( eMgMg aqs 22

)(

Power Supply

CuSO4 (aq) MgSO4 (aq)

Cell A Cell B


Specific Instructions For Section B Section B consists of eight short-answer questions numbered 1 to 8; you must answer all of these questions. This section is worth 45 marks which is approximately 69 per cent of the total available marks You should spend approximately 62 minutes on this section. The marks allotted to each question are shown at the end of each question. Questions must be answered in the spaces provided in this book. To obtain full marks for your responses you should

• Give simplified answers with an appropriate number of significant figures for all numerical questions; unsimplified answers will not be given full marks.

• Show all working in your answers to numerical questions. No credit will be given for an incorrect answer unless it is accompanied by details of the working.

• Make sure that all chemical equations are balanced and that the formulas for individual

substances include an indication of state (for example, )(2 gH ; )(sNaCl ).


QUESTION 1 Caravan refrigerators often have more than one source of energy. They can run from a

V12 car battery, or from the V240 power supply that originates from the Yallourn Power

Station in Eastern Victoria. a. Identify each source of energy as either renewable or non-renewable.

V12 battery: ____________________________________________

V240 power supply: ______________________________________

1 mark

b. Identify one advantage and one disadvantage for each source of energy. Advantage

V12 battery: ____________________________________________

V240 power supply: ______________________________________

Disadvantage

V12 battery: ____________________________________________

V240 power supply: ______________________________________

2 marks

Total 3 marks

QUESTION 2 Write a balanced equation for the reaction that occurs when hydrogen gas is bubbled

through an alkaline solution of 2NiCl .

_________________________________________________________________________

_________________________________________________________________________

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3 marks

Total 3 marks


QUESTION 3 A student determined the heat of combustion of octane using the apparatus illustrated. She measured the mass of octane burnt and the rise in temperature of the water in the calorimeter. From this data she calculated the heat of combustion.

a. Write an equation for the complete combustion of one mole of octane.

_____________________________________________________________________

_____________________________________________________________________

1 mark b. State three ways in which the student could have improved this experiment and obtained a more accurate value for the molar heat of combustion of octane.

_____________________________________________________________________

_____________________________________________________________________

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3 marks


c. How many kilojoules are absorbed in raising the temperature of the water from 17.0°C to 20.9°C?

_____________________________________________________________________

_____________________________________________________________________

1 mark d. Use these results to calculate the heating energy which would have been evolved if one mole of octane had been burnt.

_____________________________________________________________________

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2 marks

Total 7 marks


QUESTION 4 It is found experimentally, that the complete combustion of 2.00 g of gaseous ethanol,

OHCHCH 23 , produces 63.0 kJ of heat.

(a) Calculate H for the reaction: )(2)(2)(2)(23 323 gggg OHCOOOHCHCH

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2 marks (b) The heat of vaporisation of water is 44 kJ/mol. Use this information to calculate the

heat of reaction for )(2)(2)(2)(23 323 lggg OHCOOOHCHCH .

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

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2 marks

Total 4 marks


QUESTION 5 Consider the following process used in the production of biodiesel fuels.

a. (i) State the name of species A.

_____________________________________________________________________

1 mark (ii) State the process occuring at B.

_____________________________________________________________________

1 mark (iii) State the name of species C.

_____________________________________________________________________

1 mark


b. The structure of canola oil is given below.

Give the structural formula of the more saturated biodiesel molecule that can be obtained from canola oil.

1 mark c. (i) Why can’t canola oil be used directly in a diesel engine?

_____________________________________________________________________

_____________________________________________________________________

1 mark (ii) With reference to intermolecular bonding explain why a sample of biodiesel is more likely to be found as a solid at low temepratures than a sample of petrodiesel.

_____________________________________________________________________

_____________________________________________________________________

1 mark

Total 6 marks


QUESTION 6 Several experiments were carried out under standard conditions using four half cells.

The 2/ HH half cell was labelled correctly, but otherwise, it was only known that each

beaker contained a conjugate pair. The other three beakers were labelled as PP /2,

QQ /2 and RR /2

.

A number of experiments were then performed using the four half cells. During these experiments, it was observed that:

• Metal P formed at the bottom of the beaker when metal R was placed into a solution

of 2P .

• Hydrogen gas reduced both 2P and

2R to form their respective metals.

• When the 2/ HH half cell was connected to the QQ /2

half cell using a salt bridge

and wires, the reading obtained on the voltmeter was V14.0 . Metal Q was connected

to the negative terminal of the voltmeter. a. Place the four half cells into a reactivity series with the strongest oxidant at the top and the strongest reductant at the bottom.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

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_____________________________________________________________________

4 marks b. Given that these experiments were carried out under standard conditions, identify

metal Q .

_____________________________________________________________________

_____________________________________________________________________

1 mark

Total 5 marks


QUESTION 7 Chlorine and sodium hydroxide are produced by the electrolysis of concentrated sodium chloride. The net cell reaction can be represented as

)(222)( 222 aqgglaq OHHClOHCl

a. For each electrode, write the corresponding half equation. Positive electrode: ______________________________________________________ Negative electrode: _____________________________________________________

2 marks

b. (i) Calculate the volume of chlorine gas that would be produced from L00.1 of

M0.10 sodium chloride solution. Assume that the gas is collected at a

temperature of K298 and a pressure of kPa3.101 .

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2 marks

(ii) Calculate the time (in hours) required to produce this volume of chlorine gas using

a current of A20 .

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

3 marks

c. Where is the chlorine gas collected from?

_____________________________________________________________________

_____________________________________________________________________

1 mark

Total 8 marks


QUESTION 8 The following electrolytic cell was used to determine the value of the Avogadro constant.

It was noted that the charge on one electron is C19106.1 . Data recorded during the

experiment include:

Initial mass of anode: g635.0

Final mass of anode: g153.0

Current applied: A60.1

Time: min0.15

a. Calculate the number of mole of electrons transferred during the experiment.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2 marks b. (i) Using only the data given above, calculate the number of Coulombs of electricity passed through the cell during the experiment.

_____________________________________________________________________

_____________________________________________________________________

1 mark

(ii) Hence find the number of electrons that were transferred during the experiment.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2 marks

ZnSO4 (aq)

Zinc Zinc

Power Supply


c. Use your answers to a and b to determine a value for the Avogadro constant

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

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2 marks d. Would it have been better to use the change in mass of the negative electrode to determine a value of Avogadro's Constant? State one reason for your answer.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

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_____________________________________________________________________

_____________________________________________________________________

2 marks

Total 9 marks

Documents

A Multiple choice questions B Short answer questions 8 8 ... · PDF fileWhich of the following statements regarding ... The EMF of a cell ... • Make sure that all chemical equations