F3-Final-Exam Revision (Q1)

Which of the following methods can be used to obtain magnesium from magnesium compounds?

• Electrolysis of a molten magnesium compound

• Electrolysis of an aqueous solution of a magnesium compound

• Heating magnesium oxide with carbon

• Heating magnesium oxide strongly

Both radium (Ra) and calcium (Ca) belong to the same group of the Periodic Table. Which of the following statements is INCORRECT?

• Radium is a good conductor of electricity in the solid state.

• Radium atoms readily donate electrons to form Ra²⁺ ions.

• Both radium and calcium become tarnished after exposed to air for some time.

• Radium is less reactive than calcium.

Which of the following statements concerning an aluminium ore consisting mainly of Al₂O₃ is correct?

(Relative atomic masses: O = 16.0, Al = 27.0)

• Carbon can be used to extract aluminium from this ore.

• The abundance of this ore in the earth crust is very low.

• This ore contains more than 55% of aluminium by mass.

• Aluminium can be extracted from this ore due to the advancement of technology in applying electricity.

Which of the following statements concerning the extraction of metals is INCORRECT?

• Silver and oxygen form when silver oxide is heated in air.

• Lead forms a less stable oxide than aluminium, so it is easier to extract lead from its oxide compared with aluminium.

• Gold can be obtained from its ore by panning.

• Magnesium and oxygen are produced when magnesium oxide is heated with carbon.

X, Y, and Z are metals. When placed into a solution of copper(II) sulphate respectively, X and Z dissolve but Y does not. X is extracted from its ore by electrolysis. Z can be reduced by heating with carbon. Which of the following shows the reactivity of these three metals in decreasing order?

• X, Y, Z

• X, Z, Y

• Y, X, Z

• Z, Y, X

Caesium and sodium are in the same group in the Periodic Table. Which of the following statements is INCORRECT?

• The chemical formula of caesium sulphate is Cs₂SO₄.

• Caesium loses electrons to form cations.

• Caesium reacts vigorously with cold water to give hydrogen.

• Caesium burns in air to give a golden yellow flame.

Selenium (Se) is a Group VI element in the Periodic Table. Which of the following chemical formulae of selenium compounds is INCORRECT?

• H₂Se

• AlSe₃

• CSe₂

• SeCl₂

₃₈Sr is a Group II element in the Periodic Table. Its electronic configuration is

• 2, 8, 18, 10.

• 2, 8, 18, 8, 2.

• 2, 8, 8, 18, 2.

• 8, 8, 18, 2, 2.

X, Y and Z are three different metals. X and Y react with hydrochloric acid but Z does not. X reacts quickly with cold water but Y does not. The correct order of reactivity of the metals is

• X < Y < Z

• Z < Y < X

• Z < X < Y

• X < Z < Y

Which of the following species does NOT contain dative covalent bond?

• Carbon monoxide

• Ammonium ion

• Carbonate ion

• Ozone