SPM Chemistry (Quiz 3)

Which statement defines oxidation?

• Gain of electron

• Gain of hydrogen

• Loss of oxygen

• Increase in oxidation number

Which of the following is an electrolyte?

• Glucose

• Naphthalene

• Sodium chloride solution

• Glacial ethanoic acid

Which of the following reactants is most suitable for the preparation of silver chloride?

• Silver and hydrochloric acid

• Aqueous silver nitrate and aqueous sodium chloride

• Aqueous silver nitrate and sodium hydroxide

• Solid silver carbonate and hydrochloric acid

Which of the following is correct in the electrolysis of molten lead (II) bromide?

• ANODE

  Pb²⁺ + 2e --> Pb

  CATHODE

  2Br ¯ --> Br₂ + 2e

• ANODE

  2Br ¯ --> Br₂ + 2e

  CATHODE

  Pb²⁺ + 2e --> Pb

• ANODE

  Pb²⁺ --> Pb + 2e

  
  

  CATHODE

  2Br ¯ + 2e --> Br₂

• ANODE

  2Br¯ + 2e --> Br₂

  CATHODE

  Pb²⁺ --> Pb + 2e

Diagram shows the energy level diagram of a chemical reaction.

Which conclusion can be made from the diagram?

• The energy content of reactants is higher than the products

• Reaction absorb heat from surrounding

• This is a displacement reaction

• The reaction must be heated

Diagram shows the changes of iron (II) sulphate to iron (III) sulphate using bromine water.

Which of the following is true regarding the reaction?

• Iron(II) ions are reduced

• Green solution turns brown

• Bromine water is oxidized

• Iron(II) ions gain electron

Diagram shows the set-up of apparatus used to purify impure copper metal.

What would be observed after 30 minutes?

• Impurities settle to the bottom of the beaker below the anode

• The intensity of the blue colour of copper (II) sulphate solution decreases

• The pure copper cathode becomes thinner

• The impure copper anode becomes thicker

A thermochemical equation is given as below

Zn + CuSO₄ --> ZnSO₄ + Cu; ΔH = - 210 kJ mol^-1

What is the temperature increases if 50 cm³ of 0.2 mol dm^-3 of copper (II) sulphate solution is added with excess zinc?

[ c = 4.2 J g^{-1 o}C^-1 ; Density of solution = 1 g cm^-3 ]

• 0.01^oC

• 10.5^oC

• 10^oC

• 200^oC

Which factor does not affect the discharge of ions at electrodes during electrolysis of an aqueous solution?

• Position of ions in the electrochemical series

• Concentration of ions in the electrolyte

• Volume of electrolyte

• Types of electrodes

In the electrolysis of magnesium sulphate solution, MgSO₄ using carbon electrodes,

what is formed at anode?

• Hydrogen gas

• Oxygen gas

• sulphur dioxide

• Magnesium