Reactivity series and metals

Why is the reaction between magnesium and copper oxide known as the thermite reaction?

• It forms copper

• Magnesium is less reactive than copper

• It is a displacement reaction

• It releases heat

Why are sulfate ions (SO4 2-) known as spectator ions in the following equation:

Zn + CuSO4 = ZnSO4 + Cu

• They balance on both sides

• They are unchanged on both sides

• They are not needed in the reaction

• They change on both sides of the reaction

Which of the following is an example of displacement reaction?

• 2 KClO₃→KCl + O₂

• 2H₂ + O₂ →2 H₂O

• Zn + 2 HCl → ZnCl₂ + H₂

• N₂ + 3 H₂ → 2 NH₃

How can you tell that a metal is reacting with water?

• Colour change

• Bright light

• Fizzing

• It gets colder

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 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

What is the oxidizing agent of this reaction?

3Mg + N₂ → Mg₃N₂

• Mg

• Mg₃N₂

• MgN

• N₂

A chemical engineer plans to produce hydrochloric acid, which metal is best for the reaction container?

• iron

• magnesium

• copper

• zinc