Oxidation and Reduction Agents

Which statement is true of a reducing agent?

• It is oxidised as it gains electrons.

• It is oxidised as it loses electrons.

• It is reduced as it gains electrons.

• It is reduced as it loses electrons.

What is the substance that loses hydrogen in a redox reaction?

• oxidizing agent

• reducing agent

• is reduced

• decreases in oxidation number

What is the substance that loses oxygen in a redox reaction?

• oxidizing agent

• reducing agent

• is oxidized

• increases in oxidation number

When a gas changes iron(III) oxide to iron(II) oxide, the gas is

• a combustible gas

• a reducing agent

• an inert gas

• an oxidising agent

What is the colour change of acidified KMnO₄(aq) solution as a test for reducing agents?

• From green to orange

• From orange to green

• From purple to colourless

• From colourless to purple

In a redox reaction, spectator ions...

• become oxidised

• become reduced

• remain unchanged

Which gas is the strongest reducing agent?

• Br^-

• Cl^-

• F^-

• I^-

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Of the following oxides, which can be most easily reduced on a charcoal block?

^{*hint: the more reactive the metal, the more easily it loses electron to form ions, hence, the less likely will take back electron and be reduced.}

^{Eg. Potassium loses electron easily to form potassium ion. It is very difficult for potassium to gain back its electron and be reduced.*}

• calcium oxide

• copper(II) oxide

• silver oxide

• zinc oxide

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the oxidizing agent of this reaction?

3Mg + N₂ → Mg₃N₂

• Mg

• N₂

• Mg₃N₂

• MgN

What is the reducing agent of this reaction?

2Al (s) + 6H⁺ (aq) → 2Al³⁺ (aq) + 3H₂ (g)

• H⁺

• Al³⁺

• Al

• H₂