1.1 Oxidation and Reduction

Report 1 / 5

Which of the following statement is not true?

(A)		The release of electrons means that the substance is oxidised

(B)		Combustion of solid magnesium in excess oxygen is an oxidation process only

(C)		The brown spot on a peeled apple is because of oxidation

(D)		The release of hydrogen means that the substance is oxidised

Difficulty Level: Hard

Report 2 / 5

The following shows a chemical equation.

\(2HCl(aq) + Mg(s) \rightarrow MgCl_2(aq) +H_2(g)\)

Which of the following is true regarding this chemical reaction?

Difficulty Level: Medium

Report 3 / 5

Which of the following is a not redox reaction?

(A)		\(Zn +CuSO_4 \rightarrow ZnSO_4 + Cu\)

(B)		\(HCl + NaOH \rightarrow NaCl +H_2O\)

(C)		\(2HNO_3 + Zn \rightarrow Zn(NO_3)_2+H_2\)

(D)		\(2Mg + O_2 \rightarrow 2MgO\)

Difficulty Level: Hard

Report 4 / 5

Which of the following is the observation for the reaction of magnesium plate with copper(II) sulphate?

I.		The magnesium plate becomes thinner

II.		The colour of the solution changes from colourless to blue

III.		Blue precipitate is formed

IV.		The colour of the solution changes from blue to colourless

Difficulty Level: Medium

Report 5 / 5

Which of the following change of colour is indicating the oxidation of iron(II) ion to iron(III) ion?

(A)		Colourless to blue

(B)		Green to brown

(C)		Blue to colourless

(D)		Brown to green

Difficulty Level: Medium