Reactivity of metals

Apréndelo jugando

Responde estas preguntas para ganar energía, luego pesca y explora. Sin cuenta.

Para educadores: diapositivas de la lección, apuntes de repaso listos para usar sobre Reactivity of metals (Science, Chemistry) — úsalos en tu lección, o presenta el tema como una actividad interactiva de clase que tus aprendices juegan como un juego en vivo.

Apuntes de la lección

Metal Oxides and Redox

Metals react with oxygen in the air to produce metal oxides.
Oxidation is the addition of oxygen to a substance; reduction is the removal of oxygen from a substance.
These reactions are called redox reactions because oxidation and reduction occur simultaneously.
Example: copper reacts with oxygen to form black copper oxide: 2Cu + O₂ → 2CuO. Copper has been oxidised.
Example: zinc oxide reacts with carbon: ZnO + C → Zn + CO. Zinc oxide is reduced (loses oxygen) and carbon is oxidised (gains oxygen).

The Reactivity Series

The reactivity series arranges metals in order of their reactivity, from most reactive to least reactive.
Order of reactivity: potassium, sodium, lithium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold.
Metal atoms form positive ions by losing electrons when they react.
The more reactive a metal, the more easily it loses electrons to form a positive ion.
Non-metals carbon and hydrogen are included in the series because they help predict how metals are extracted.

The reactivity series of metals including hydrogen and carbon

Reactions of Metals with Water

Metals above hydrogen in the reactivity series react with water.
General equation: metal + water → metal hydroxide + hydrogen.
Potassium reacts violently, sodium reacts quickly, lithium and calcium react less strongly.
Magnesium, zinc and iron react very slowly with cold water; copper does not react.
Example: calcium + water → calcium hydroxide + hydrogen: Ca + 2H₂O → Ca(OH)₂ + H₂.

Reactions of Metals with Dilute Acids

Metals above hydrogen in the reactivity series react with dilute acids.
General equation: metal + acid → salt + hydrogen.
The more reactive the metal, the more vigorous the reaction.
Potassium and sodium react violently; magnesium, zinc and iron react less strongly; copper does not react.
Example: magnesium + hydrochloric acid → magnesium chloride + hydrogen: Mg + 2HCl → MgCl₂ + H₂.

Displacement Reactions

A more reactive metal can displace a less reactive metal from its compound.
Displacement can occur between a metal and a metal oxide (by heating) or a metal and an aqueous solution of a metal salt.
Example: zinc + copper oxide → zinc oxide + copper: Zn + CuO → ZnO + Cu. Zinc is the reducing agent.
Example: magnesium + copper sulfate → magnesium sulfate + copper: Mg + CuSO₄ → MgSO₄ + Cu. The blue colour of copper sulfate fades.
The thermite reaction: iron(III) oxide + aluminium → iron + aluminium oxide: Fe₂O₃ + 2Al → 2Fe + Al₂O₃. Aluminium is more reactive than iron.

Displacement of copper by magnesium

Extraction of Metals and Reduction

Most metals are found in ores; a metal ore is a rock containing enough metal to make extraction worthwhile.
Unreactive metals like gold and platinum are found as native metals (uncombined elements).
Metals above carbon in the reactivity series are extracted by electrolysis (e.g., aluminium).
Metals below carbon can be extracted by heating with carbon (reduction), e.g., zinc, iron, copper.
Extraction of a metal from its oxide is a reduction process because oxygen is removed.
Example: zinc oxide + carbon → zinc + carbon dioxide: ZnO + C → Zn + CO.

Oxidation and Reduction in Terms of Electrons

Oxidation is the loss of electrons; reduction is the gain of electrons (OIL RIG).
In a redox reaction, one species is oxidised and another is reduced.
Example: iron + copper sulfate → iron(II) sulfate + copper: Fe + CuSO₄ → FeSO₄ + Cu.
Ionic equation: Fe + Cu²⁺ → Fe²⁺ + Cu. Sulfate ions are spectator ions.
Half equations: Fe → Fe²⁺ + 2e⁻ (oxidation); Cu²⁺ + 2e⁻ → Cu (reduction).

Redox reaction between Fe and Cu²⁺ shown by electron transfer

Electrolysis and Redox

During electrolysis, oxidation and reduction occur at the electrodes.
At the cathode (negative electrode), positive ions gain electrons (reduction).
At the anode (positive electrode), negative ions lose electrons (oxidation).
Example at cathode: Pb²⁺ + 2e⁻ → Pb (reduction).
Example at anode: 2Br⁻ → Br₂ + 2e⁻ (oxidation).

Diapositivas

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

REGÍSTRATE — GRATIS INICIAR SESIÓN

Preguntas de práctica

Vista previa gratis — 8 de 59 preguntas. Regístrate para verlas todas.

1.In terms of oxygen, what name is given to the loss of oxygen from a substance?
Easy
- AOxidation
- BReduction
- CNeutralisation
- DDisplacement
2.In terms of oxygen, what name is given to the gain of oxygen by a substance?
Easy
- AReduction
- BOxidation
- CElectrolysis
- DDisplacement
3.The reaction of nickel(II) oxide with carbon is a redox reaction. Which statement explains whether carbon is oxidised or reduced?
Medium
- ACarbon is oxidised because it gains oxygen
- BCarbon is reduced because it gains oxygen
- CCarbon is oxidised because it loses oxygen
- DCarbon is reduced because it loses oxygen
4.Which two non-metals commonly appear in the reactivity series? (select all that apply)
Medium
- ACarbon
- BHydrogen
- COxygen
- DNitrogen
- EChlorine
5.Place these metals in order from most reactive to least reactive.
Medium
- gold
- iron
- lithium
- magnesium
6.Sodium is above copper in the reactivity series. What type of reaction is: 2Na + CuO → Cu + Na₂O?
Medium
- AReduction
- BOxidation
- CNeutralisation
- DDisplacement
7.Which metals can give a coloured flame when they react with cold water?
Medium
- AAluminium and zinc
- BCopper and zinc
- CPotassium and sodium
- DMagnesium and iron
8.Which statement about displacement reactions is correct?
Easy
- AA less reactive metal displaces a more reactive metal from its compounds
- BA more reactive metal displaces a less reactive metal from its compounds
- CDisplacement reactions require heating
- DDisplacement reactions are easier to see when they are in solution

Más preguntas

9.Which metal cannot be extracted from its ore by reduction with carbon?
Medium
- AAluminium
- BCopper
- CZinc
- DIron
10.Match each metal to the correct observation when it reacts with cold water.
Medium
- Potassium
- Sodium
- Calcium
- Iron
- Reacts violently
- Reacts quickly
- Reacts less strongly
- Slow rusting
11.Which of the following metals react with cold water? (select all that apply)
Medium
- APotassium
- BCopper
- CCalcium
- DGold
- ESilver
12.Place these metals in order of reactivity with dilute acid, from most reactive to least reactive.
Medium
- Magnesium
- Zinc
- Iron
- Copper
13.Which statements about the reactivity series are correct? (select all that apply)
Medium
- AMetals are arranged in order of decreasing reactivity.
- BCarbon and hydrogen are non-metals included in the series.
- CA more reactive metal can displace a less reactive metal from its compounds.
- DAll metals in the series react with cold water.
- EThe reactivity series shows the melting points of metals.
14.Match each metal with its main extraction method.
Medium
- Potassium
- Zinc
- Gold
- Electrolysis
- Reduction by carbon
- Found as native metal
15.Why is aluminium extracted by electrolysis rather than by reduction with carbon?
Medium
- AAluminium is more reactive than carbon.
- BAluminium is less reactive than carbon.
- CAluminium is found as a native metal.
- DAluminium oxide cannot be reduced by any method.
16.Gold is found in the Earth's crust as the unreacted metal itself.
Easy
True or false?
17.In the reaction ZnO + C → Zn + CO, which statements are correct? (select all that apply)
Hard
- AZinc oxide is reduced.
- BCarbon is oxidised.
- CZinc oxide is oxidised.
- DCarbon is reduced.
- EZinc is oxidised.
18.Which statement defines oxidation in terms of electrons?
Medium
- AOxidation is the loss of electrons.
- BOxidation is the gain of electrons.
- COxidation is the loss of oxygen.
- DOxidation is the gain of protons.
19.In the half equation Zn²⁺ + 2e⁻ → Zn, what has happened to the zinc ion?
Medium
- AIt has been reduced.
- BIt has been oxidised.
- CIt has been displaced.
- DIt has been neutralised.
20.A student places a piece of metal X into a solution of a compound of metal Y. A reaction occurs and a solid layer of Y forms on X. Which statement is correct?
Medium
- AX is more reactive than Y and displaces it
- BY is more reactive than X and displaces it
- CX is less reactive than Y so no displacement occurs
- DThe reaction is not a displacement reaction because no heating is used
21.A student adds a metal to dilute hydrochloric acid. Bubbles of gas are seen and the metal gradually disappears. Which statements could explain these observations? (select all that apply)
Hard
- AThe metal is above hydrogen in the reactivity series
- BThe gas produced is hydrogen
- CThe metal is below hydrogen in the reactivity series
- DA salt is formed as well as hydrogen
- EThe gas produced is oxygen
22.Match each metal with the correct observation when it is added to cold water.
Medium
- Potassium
- Sodium
- Calcium
- Iron
- Reacts violently
- Reacts quickly
- Reacts less strongly
- Slow rusting
23.The thermite reaction is used to weld rail tracks: Fe₂O₃ + 2Al → 2Fe + Al₂O₃. Which species is reduced and why?
Medium
- AIron(III) oxide, because it loses oxygen
- BAluminium, because it gains oxygen
- CIron(III) oxide, because it gains oxygen
- DAluminium, because it loses oxygen
24.In the reaction ZnO + C → Zn + CO, carbon is oxidised because it gains oxygen.
Easy
True or false?
25.A student reacts four metals with dilute hydrochloric acid. The metals are listed with their observations. Place them in order from most reactive to least reactive.
Medium
- Metal W: reacts violently
- Metal X: reacts vigorously
- Metal Y: reacts less strongly
- Metal Z: no reaction
26.A student reacts zinc with copper sulfate solution. The blue colour of the copper sulfate fades and a pink-brown solid forms. What is the correct word equation for this reaction?
Medium
- Azinc + copper sulfate → zinc sulfate + copper
- Bcopper + zinc sulfate → copper sulfate + zinc
- Czinc + copper sulfate → zinc oxide + copper
- Dzinc + copper sulfate → zinc chloride + copper
27.Carbon is placed in the reactivity series because it can act as a cheap reducing agent to extract some metals from their oxides.
Easy
True or false?
28.Which statements about reduction are correct? (select all that apply)
Medium
- AReduction can be defined as the loss of oxygen from a substance.
- BReduction can be defined as the gain of electrons.
- CReduction is the gain of oxygen by a substance.
- DReduction is the loss of electrons.
- EReduction always produces a gas.
29.A student investigates the reactivity of three metals by adding each metal powder to solutions of the other metal sulfates. The student uses 1 g of metal powder and 10 cm³ of metal sulfate solution, shakes, waits 1 minute and observes. Which change to the method would make the comparison of reactivity least fair?
Medium
- AUsing a different mass of metal powder for each metal
- BUsing the same volume of metal sulfate solution for each test
- CShaking each test tube slightly
- DWaiting 1 minute before observing each test
30.A student reacts four metals with dilute hydrochloric acid and records the observations. Which observation indicates the most reactive metal?
Medium
- AVigorous effervescence and the metal disappears quickly
- BSlow bubbles forming over several minutes
- CNo visible reaction
- DThe metal sinks to the bottom of the test tube
31.Which statements about the reaction of metals with dilute acids are correct? (select all that apply)
Medium
- AMetals above hydrogen in the reactivity series react with dilute acids.
- BCopper reacts vigorously with dilute hydrochloric acid.
- CThe reaction produces a salt and hydrogen gas.
- DThe more reactive the metal, the more vigorous the reaction.
- EGold reacts with dilute acids to produce gold chloride and hydrogen.
32.Aluminium is high in the reactivity series but does not react with water because it has a protective oxide layer.
Easy
True or false?
33.A student reacts four metals with dilute hydrochloric acid. The observations are: Metal A: no reaction. Metal B: vigorous effervescence. Metal C: slow bubbles. Metal D: rapid effervescence. Place the metals in order from most reactive to least reactive.
Medium
- Metal A
- Metal B
- Metal C
- Metal D
34.Which species is oxidised in this reaction?
Medium
- AZinc
- BCopper ion
- CSulfate ion
- DZinc ion
35.Which half-equation represents the reduction taking place?
Medium
- AZn → Zn²⁺ + 2e⁻
- BCu²⁺ + 2e⁻ → Cu
- CZn²⁺ + 2e⁻ → Zn
- DCu → Cu²⁺ + 2e⁻
36.A student sets up an experiment to compare the reactivity of iron, copper, and zinc by adding each metal to solutions of their sulfates. The results show that zinc reacts with iron sulfate and copper sulfate, iron reacts with copper sulfate only, and copper does not react with either. Which conclusion is correct?
Hard
- AReactivity order: zinc > iron > copper
- BReactivity order: copper > iron > zinc
- CReactivity order: iron > zinc > copper
- DReactivity order: zinc > copper > iron
37.Which statements about oxidation and reduction in terms of oxygen are correct? (select all that apply)
Medium
- AOxidation is the addition of oxygen to a substance.
- BReduction is the addition of oxygen to a substance.
- CRedox reactions involve both oxidation and reduction occurring together.
- DReduction is the removal of oxygen from a substance.
- EOxidation and reduction always happen in separate reactions.
38.Which of the following is the correct definition of a native metal?
Easy
- AA metal that is found uncombined in the Earth's crust.
- BA metal that is extracted by electrolysis.
- CA metal that reacts vigorously with water.
- DA metal that is always found as an oxide ore.
39.The reactivity series lists metals in order of increasing reactivity from top to bottom.
Easy
True or false?
40.Which of the following is a correct general equation for the reaction of a metal with a dilute acid?
Medium
- Ametal + acid → metal salt + hydrogen
- Bmetal + acid → metal oxide + hydrogen
- Cmetal + acid → metal hydroxide + hydrogen
- Dmetal + acid → metal salt + water
41.Name the compound formed when cobalt reacts with oxygen.
Easy
42.Complete the word equation for the extraction of nickel from nickel(II) oxide using carbon.
Easy
Nickel(II) oxide + carbon → ____ + ____
43.Complete the sentences about redox in terms of oxygen.
Easy
In terms of oxygen, ____ is the loss of oxygen and ____ is the gain of oxygen.
44.How many electrons are gained by a copper(II) ion when it is reduced to copper metal?
Medium
45.A student investigates the reaction of zinc with copper sulfate solution. In the balanced symbol equation Zn + CuSO₄ → ZnSO₄ + Cu, how many electrons does each copper ion gain when it is displaced?
Medium
46.Complete the word equation for the reaction of calcium with cold water.
Medium
calcium + water → calcium ____ + ____
47.Name the non-metal that is included in the reactivity series because it is a cheap reducing agent used to extract metals from their oxides.
Medium
48.Complete the word equation for the reaction of magnesium with dilute sulfuric acid.
Easy
magnesium + sulfuric acid → magnesium ____ + ____
49.Complete the word equation for the reaction of potassium with cold water.
Easy
potassium + water → potassium ____ + ____
50.Complete the word equation for the reaction of iron with dilute hydrochloric acid.
Easy
iron + hydrochloric acid → iron(II) ____ + ____
51.Complete the word equation for the displacement reaction between magnesium and silver nitrate.
Easy
magnesium + silver nitrate → ____ + ____
52.Complete the sentences about redox in terms of electrons.
Easy
In terms of electrons, ____ is the loss of electrons. In terms of electrons, ____ is the gain of electrons.
53.The thermite reaction of aluminium with iron oxide produces molten iron: 2Al + Fe₂O₃ → 2Fe + Al₂O₃. Identify which chemical is reduced and give a reason for your answer.
Medium
54.Explain why gold is found in its unreacted form in the Earth's crust.
Hard
55.Explain why carbon can be used to extract zinc from zinc oxide but cannot be used to extract aluminium from aluminium oxide.
Hard
56.Explain why calcium can displace zinc from zinc sulfate solution, but zinc cannot displace calcium from calcium chloride solution.
Medium
57.Explain why aluminium is extracted by electrolysis rather than by reduction with carbon.
Hard
58.How many electrons are gained by a copper(II) ion when it is reduced to copper metal?
Medium
- A1
- B3
- C4
- D2
59.A student investigates the reaction of zinc with copper sulfate solution. In the balanced symbol equation Zn + CuSO₄ → ZnSO₄ + Cu, how many electrons does each copper ion gain when it is displaced?
Medium
- A4 electrons
- B2 electrons
- C3 electrons
- D1 electrons

Tarjetas

In terms of oxygen, what is oxidation?

Oxidation is the gain of oxygen by an element or compound.

In terms of oxygen, what is reduction?

Reduction is the loss of oxygen from an element or compound.

Why is the reaction 2Cu + O₂ → 2CuO an oxidation reaction?

Copper gains oxygen to form copper oxide, so copper has been oxidised.

In the reaction ZnO + C → Zn + CO, which substance is reduced and why?

Zinc oxide is reduced because it loses oxygen.

In the reaction ZnO + C → Zn + CO, which substance is oxidised and why?

Carbon is oxidised because it gains oxygen to form carbon monoxide.

What is a redox reaction?

A reaction in which oxidation and reduction happen at the same time.

How are metals arranged in the reactivity series?

Metals are placed in decreasing order of reactivity, from most reactive at the top to least reactive at the bottom.

Why do metal atoms form positive ions when they react?

Metal atoms lose electrons to form positive ions; the more easily a metal loses electrons, the more reactive it is.

Which two non-metals are commonly included in the reactivity series?

Carbon and hydrogen.

Why is carbon included in the reactivity series?

Carbon is a cheap reducing agent that can remove oxygen from metal oxide ores, so its position shows whether a metal oxide can be reduced by carbon.

Why is hydrogen included in the reactivity series?

Whether a metal reacts with water or dilute acid depends on its position relative to hydrogen.

Give the general word equation for a metal reacting with cold water.

metal + water → metal hydroxide + hydrogen

Give the general word equation for a metal reacting with a dilute acid.

metal + acid → metal salt + hydrogen

Which metals react with cold water to form a metal hydroxide and hydrogen?

Metals above hydrogen in the reactivity series, such as potassium, sodium, lithium and calcium.

Which metals will NOT react with dilute acids?

Metals below hydrogen in the reactivity series, such as copper.

Describe the reaction of potassium and sodium with water.

Potassium reacts violently and sodium reacts quickly, both producing a metal hydroxide and hydrogen.

Describe the reaction of magnesium, zinc and iron with cold water.

Their reactions with cold water are very slow; iron shows slow rusting.

Why does aluminium not react with water even though it is high in the reactivity series?

It has a protective oxide layer that prevents reaction with water and makes its reaction with dilute acids quite slow.

What is a displacement reaction?

A reaction in which a more reactive metal displaces a less reactive metal from its compound.

What is the rule for whether a displacement reaction occurs?

It occurs when the solid metal is more reactive than the metal in the compound.

In the reaction Zn + CuO → ZnO + Cu, which metal is the reducing agent?

Zinc, because it is more reactive than copper and removes oxygen from copper(II) oxide.

What is the thermite reaction and what is it used for?

Iron(III) oxide reacts with aluminium to form iron and aluminium oxide; it is highly exothermic and the molten iron is used for welding rail tracks.

Write the equation for the thermite reaction.

Fe₂O₃ + 2Al → 2Fe + Al₂O₃

In Mg + CuSO₄ → MgSO₄ + Cu, what colour change is seen?

The blue colour of the copper sulfate solution fades as colourless magnesium sulfate forms, and copper coats the magnesium.

What is a metal ore?

A rock that contains enough of a metal to make it worthwhile extracting.

What is a native metal? Give examples.

A metal found uncombined in the Earth's crust because it is unreactive; examples include gold and platinum.

Why are unreactive metals such as gold found as the metal itself?

They do not easily react with other substances because of their chemical stability, so they need no chemical extraction.

Which metals are extracted by electrolysis and why?

Metals above carbon in the reactivity series, such as potassium, sodium, calcium, magnesium and aluminium, because they are too reactive to be reduced by carbon.

Which metals are extracted by heating with carbon and why?

Metals below carbon, such as zinc, iron and copper, because carbon is a cheap reducing agent that removes the oxygen from their oxides.

Give the general word equation for extracting a metal oxide with carbon.

metal oxide + carbon → metal + carbon dioxide

Why is electrolysis an expensive extraction method?

It requires large amounts of electricity.

In terms of electrons, what is oxidation?

Oxidation is the loss of electrons.

In terms of electrons, what is reduction?

Reduction is the gain of electrons.

What does the mnemonic OIL RIG stand for?

Oxidation Is Loss, Reduction Is Gain (of electrons).

Write the half equation for iron being oxidised in Fe + CuSO₄ → FeSO₄ + Cu.

Fe → Fe²⁺ + 2e⁻

Write the half equation for copper ions being reduced in Fe + CuSO₄ → FeSO₄ + Cu.

Cu²⁺ + 2e⁻ → Cu

In Fe + CuSO₄ → FeSO₄ + Cu, which species is oxidised and which is reduced?

Iron is oxidised (loses electrons) and copper ions are reduced (gain electrons).

What are spectator ions?

Ions that appear unchanged on both sides of an ionic equation and take no part in the reaction, so they can be removed.

In electrolysis, where does reduction occur?

At the cathode (negative electrode), where positive ions gain electrons.

In electrolysis, where does oxidation occur?

At the anode (positive electrode), where negative ions lose electrons.

Give the half equation for reduction at the cathode during electrolysis of lead compounds.

Pb²⁺ + 2e⁻ → Pb

Give the half equation for oxidation at the anode during electrolysis of bromide compounds.

2Br⁻ → Br₂ + 2e⁻

In V³⁺ + Fe²⁺ → V⁴⁺ + Fe, which change is oxidation?

V³⁺ to V⁴⁺ is oxidation because vanadium loses an electron.

Unlock all 59 questions, flashcards & more

Crea una cuenta gratis para ver todas las preguntas, las diapositivas, las tarjetas y los apuntes de repaso de este tema.

REGÍSTRATE — GRATIS INICIAR SESIÓN

Exámenes anteriores

La práctica con exámenes anteriores de este tema llegará pronto.

Próximamente