Chemistry Quiz Chapter 6 Form 4 @mohdnorihwan.blogspot.com 622z44

Chapter 6 Electrochemistry Paper 1 Answer all the questions. 1

The figure below shows an electrolysis of dilute sulphuric acid. X

platinum electrodes

dilute sulphuric acid +

–

What could be gas X and the half-equation occuring at the cathode? A Carbon dioxide, C + O2→ CO2 B Hydrogen, 2H+ + 2e- → H2 C Oxygen, 4OH- → H2O + O2 + 4eD Sulphur dioxide, SO42- → SO2 + O2 + 2e2

In the electrolysis of molten lead (II) bromide which of the following correctly describes the ions and the product at the anode? Lead(II) bromide Product A Negative lead(II) ions and Bromine molecules positive bromide ions B Positive lead(II) ions and Bromine atoms negative bromide ions C Lead(II) bromide molecules Bromine molecules D Positive lead(II) ions and Bromine molecules negative bromide ions

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In the electrolysis of an aqueous solution R, the following products are formed. At the cathode : a brown solid At the anode : a pale greenish yellow gas that bleaches a piece of damp litmus paper Which of the following could be R? A Dilute hydrochloric acid B Molten lead(II) chloride C Dilute copper(II) chloride solution D Molten copper(II) chloride

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The following solutions are electrolysed using inert electrodes. solution X : dilute sulphuric acid solution Y : aqueous copper(II) chloride solution solution Z : dilute hydrochloric acid Which solutions would produce a colourless gas at the anode? A Solutions X and Z B Solutions X and Y C Solutions Y and Z D Solution X

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A solid layer of element X is formed at the cathode when an aqueous solution of X is electrolysed with carbon electrodes. Which statements about element X is correct? I Ions of X are discharged at the cathode II Element X is a metal III Ions of X lose electrons at the cathode IV Element X must be below hydrogen in the electrochemical series A I and III only B I and IV only C I, II and IV only D II,III and IV only

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What are the products formed when concentrated aqueous sodium chloride solution is electrolysed? At the anode At the cathode A Chlorine Hydrogen B Chlorine Lithium C Oxygen and water Hydrogen D Oxygen and water Lithium

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A large-scale production of aluminium involves purified bauxite, Al2O3, in cryolite. How is the aluminium extracted from bauxite in industry? A Electrolysis of an aqueous solution of the Al2O3 B Electrolysis of the molten mixture of Al2O3 and cryolite C Fractional distillation of the mixture of Al2O3 and cryolite D Heating of bauxite and cryolite

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A metal spoon is electroplated with silver using silver nitrate solution as the electrolyte. Which of the following should be used as the negative electrode? A Graphite B Spoon C Platinum D Silver

9

An electric current is ed through copper(II) chloride solution using the apparatus shown below.

carbon electrode X

carbon electrode Y copper(II) chloride solution

What happens at electrode X? A Chloride ions are discharged B Chlorine is ionised C Copper ions are discharged D Copper metal is deposited

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10 The ammeter in the figure below showed that no current is flowing in the circuit. A

ammeter

liquid X

What is liquid X? A Aqueous sodium chloride solution B Aqueous sodium hydroxide solution C Dilute sulphuric acid D Tetrachloromethane Questions 11–12 are based on the figure below. 11 The figure below shows a simple cell. V e– voltmeter

metal X

metal Y dilute sulphuric acid

Which of the following pairs of metals would electrons flow as shown? X Y A Copper Calcium B Iron Magnesium C Zinc Aluminium D Zinc Iron 12 Which of the following will produce the highest reading on the voltmeter? Cathode Anode Solution A Copper Copper Dilute sulphuric acid B Copper Zinc Dilute sulphuric acid C Copper Iron Sugar solution D Copper Silver Distilled water 13 A piece of zinc foil is placed in a mixture of aqueous iron(II) sulphate solution and aqueous sodium sulphate soulution. Which substance is displaced from the mixture? A Iron B Hydrogen C Sodium D Oxygen

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14 What changes would take place when dilute sulphuric acid is electrolysed with platinum electrodes? I Hydrogen gas is produced at cathode II The concentration of the acid decreases III The solution loses water IV Sulphate ions are discharged A I and II only B II and IV only C I and III only D I,II,III and IV 15 Strips of metal X are dipped into two solutions as shown below. metal X

metal X

aqueous iron(II) sulphate solution

aqueous copper(II) nitrate solution

A metallic deposit appears on both strips. What could metal X be? I Lead II Zinc III Magnesium IV Aluminium A I and II only B II and III only C II,III and IV only D I,II,III and IV 16 A voltage is produced by the apparatus shown below. V metal X

XCl2(aq)

metal Y

YCl2(aq)

Which pair of metals X and Y will generate the highest voltage? X Y A Iron Copper B Magnesium Zinc C Aluminium Copper D Zinc Iron

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17 Which of the following is true about the electrochemical series? I It is an arrangement of elements based on their tendencies to form ions II It is can be constructed based on the potential difference between two metals III It is can be constructed based on the displacement reaction of metals IV It is can be used to determine the terminals of voltaic cells A I and II only B II and III only C I,II and III only D I,II,III and IV 18 Which of the following elements are obtained commercially by electrolysis? I Sodium II Aluminium III Iron IV Tin A I and II only B II and III only C I,II and III only D I,II,III and IV 19 The figure below shows an apparatus set-up for the electrolysis of sodium chloride solution. bulb

electrodes

aqueous sodium chloride solution

Which of the following electrode, could cause the bulb to light up? A Carbon electrode B Platinum electrode C Copper and magnesium electrodes D Zinc and carbon electrodes 20 Which of the following conducts electricity but remains chemically unchanged? A Pure ethanoic acid B Copper C Molten lead(II) bromide D Aqueous copper(II) sulphate solution

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