Graphite and diamond, both allotropes of carbon, exhibit unique structures and properties that make them invaluable in various industrial and technological applications. This article explores their uses, aligning with the Cambridge IGCSE Chemistry curriculum, specifically within the chapter on Giant Covalent Structures under the unit ‘Atoms, Elements, and Compounds’. Understanding the applications of these carbon forms is essential for grasping their significance in both everyday life and advanced scientific contexts.

Key Concepts

Graphite: Structure and Properties

Graphite consists of layers of carbon atoms arranged in a hexagonal lattice. Each carbon atom is bonded to three others, forming strong covalent bonds within layers, while weaker van der Waals forces hold the layers together. This layered structure grants graphite its characteristic properties:

Lubrication: The weak interlayer forces allow layers to slide over each other easily, making graphite an excellent lubricant.
Malleability: Graphite can be molded into various shapes without breaking due to its layered structure.
Electrical Conductivity: The delocalized electrons within the layers facilitate the flow of electric current.
Thermal Conductivity: Graphite efficiently conducts heat along the planes of its layers.

Diamond: Structure and Properties

In contrast, diamond has a three-dimensional tetrahedral structure where each carbon atom forms four strong covalent bonds with neighboring carbon atoms. This robust network results in diamond's exceptional properties:

Hardness: Diamond is the hardest known natural material, making it ideal for cutting and grinding tools.
Thermal Conductivity: Despite being an electrical insulator, diamond conducts heat exceptionally well, surpassing many metals.
Optical Properties: Diamond's high refractive index and dispersion make it highly valued in gemstones.
Electrical Insulation: Unlike graphite, diamond does not conduct electricity, making it useful in insulating applications.

Applications of Graphite

Graphite's unique properties make it suitable for a wide range of applications:

Pencil Lead: Graphite mixed with clay is used as the writing medium in pencils due to its ability to leave marks on paper.
Lubricants: Graphite powder is used as a dry lubricant in machinery where traditional lubricants may fail.
Refractories: Due to its high melting point, graphite is used in making refractory materials for high-temperature environments.
Batteries: Graphite serves as an anode material in lithium-ion batteries, essential for portable electronics and electric vehicles.
Electrodes: In electric arc furnaces, graphite electrodes are used for melting and refining metals.

Applications of Diamond

Diamond's superior properties enable its use in various advanced applications:

Cutting and Drilling Tools: Industrial-grade diamonds are used in saws, drills, and grinding wheels for their unparalleled hardness.
Jewelry: Gem-quality diamonds are prized for their brilliance and used extensively in rings, necklaces, and other ornaments.
Heat Sinks: Diamond's excellent thermal conductivity is utilized in electronic devices to dissipate heat efficiently.
Optical Components: Synthetic diamonds are used in high-precision lenses and windows for their transparency and durability.
Quantum Computing: Diamonds with nitrogen-vacancy centers are explored for applications in quantum computing and advanced sensing technologies.

Environmental and Economic Impact

The extraction and production of graphite and diamond have significant environmental and economic implications:

Graphite Mining: Natural graphite mining can lead to habitat destruction and pollution if not managed sustainably. However, synthetic graphite production poses its own environmental challenges, including high energy consumption.
Diamond Mining: Diamond extraction has historically been associated with ethical concerns, such as conflict diamonds. Sustainable and fair mining practices are crucial to mitigate these issues.
Market Value: Diamonds hold substantial economic value, especially in the luxury goods market. Graphite's role in emerging technologies like batteries also drives its market demand.

Safety and Handling

Both graphite and diamond require specific safety measures during handling and processing:

Graphite: While generally non-toxic, graphite dust can be hazardous if inhaled. Proper ventilation and protective equipment are necessary during machining and grinding.
Diamond: Industrial diamond processing can generate fine particles that pose respiratory risks. Additionally, the high temperatures required for synthetic diamond creation necessitate stringent safety protocols.

Advanced Concepts

Thermal and Electrical Conductivity in Graphite and Diamond

The thermal and electrical conductivities of graphite and diamond are pivotal to their applications. Graphite's layered structure allows electrons to move freely within the planes, resulting in high electrical conductivity. This property is exploited in applications like electrodes and battery anodes. Additionally, graphite's ability to conduct heat efficiently along the planes makes it useful for heat dissipation in electronic devices.

In contrast, diamond exhibits exceptional thermal conductivity, even surpassing metals like copper. This makes diamond an ideal material for heat sinks in high-performance electronics. However, unlike graphite, diamond is an electrical insulator due to the absence of free electrons, limiting its use in electrical applications but beneficial for insulating purposes.

Mathematically, the thermal conductivity ($k$) can be expressed as:

$$ k = \frac{1}{3} C_v v l $$

Where:

$C_v$: Specific heat capacity at constant volume
$v$: Average speed of phonons
$l$: Mean free path of phonons

Graphite and diamond differ significantly in these parameters. Diamond's strong covalent bonds result in higher phonon velocities and longer mean free paths, contributing to its superior thermal conductivity.

Synthesis of Graphite and Diamond

The synthesis of graphite and diamond involves different processes due to their distinct structures:

Graphite Synthesis: Graphite can be produced synthetically through methods like the Acheson process, which involves the heating of carbon-rich materials in an electric furnace. Synthetic graphite is preferred for applications requiring high purity and controlled properties.
Diamond Synthesis: Synthetic diamond production primarily relies on two methods:
- High-Pressure High-Temperature (HPHT) Method: This approach mimics the natural formation of diamond by subjecting carbon to extreme pressures and temperatures, facilitating the transformation into diamond.
- Chemical Vapor Deposition (CVD): CVD involves decomposing a carbon-containing gas in a vacuum chamber, allowing carbon atoms to deposit and form diamond layers. This method enables precise control over diamond thickness and quality.

Interdisciplinary Connections

The applications of graphite and diamond extend beyond chemistry into various scientific and engineering disciplines:

Materials Science: Understanding the structural differences between graphite and diamond informs the development of composite materials with tailored properties for specific applications.
Electronics Engineering: Graphite's conductivity and diamond's thermal properties are leveraged in designing electronic components that require efficient heat management and electrical performance.
Mechanical Engineering: The hardness and wear resistance of diamond make it essential in designing cutting tools and machinery parts subjected to high stress and wear.
Environmental Science: The impact of graphite and diamond mining on ecosystems requires collaboration between chemists, environmental scientists, and policymakers to ensure sustainable practices.

Economic Implications and Future Prospects

The demand for graphite and diamond is influenced by technological advancements and market trends:

Graphite in Energy Storage: The rise of electric vehicles and renewable energy solutions has increased the demand for graphite in lithium-ion batteries. Innovations in battery technology may further enhance graphite's economic significance.
Diamond in Quantum Technologies: Emerging fields like quantum computing utilize synthetic diamonds with specific defects, such as nitrogen-vacancy centers, for qubit implementation and advanced sensing applications. This represents a growing market segment for diamond materials.
Recycling and Sustainability: As environmental concerns intensify, recycling graphite from used batteries and developing sustainable diamond synthesis methods are becoming critical areas of research and development.

Challenges in Utilization

Despite their valuable properties, the utilization of graphite and diamond faces several challenges:

Resource Availability: High-quality natural graphite and diamond resources are limited, necessitating the development of efficient synthetic production methods to meet industrial demand.
Cost: The synthesis of diamond, particularly at high purity and specific qualities required for technological applications, involves significant costs. Reducing production expenses remains a key challenge.
Environmental Impact: Both graphite and diamond mining and synthesis can have adverse environmental effects. Developing greener production techniques and enforcing sustainable mining practices are essential to mitigate these impacts.
Technological Limitations: Integrating graphite and diamond into advanced technologies requires overcoming technical barriers related to material compatibility, performance under operational conditions, and scalability of manufacturing processes.

Comparison Table

Property	Graphite	Diamond
Structure	Layered hexagonal lattice where each carbon atom is bonded to three others.	Tetrahedral three-dimensional network where each carbon atom is bonded to four others.
Hardness	Soft and slippery.	Hardest known natural material.
Electrical Conductivity	Good conductor of electricity.	Electrical insulator.
Thermal Conductivity	Good conductor of heat along the layers.	Excellent conductor of heat.
Uses	Pencil lead, lubricants, electrodes, batteries, refractories.	Jewelry, cutting tools, heat sinks, optical components, quantum computing.
Appearance	Black, lustrous, flaky material.	Transparent, highly refractive gemstone.
Cost	Relatively inexpensive.	Expensive, especially for gem-quality diamonds.
Environmental Impact	Mining can lead to habitat destruction and pollution.	Mining and synthesis can cause significant environmental degradation if not managed sustainably.

Summary and Key Takeaways

Graphite and diamond are distinct allotropes of carbon with unique structures and properties.
Graphite's layered structure grants it electrical conductivity and lubricating properties, making it ideal for applications like electrodes and pencils.
Diamond's three-dimensional tetrahedral structure results in unmatched hardness and thermal conductivity, suitable for cutting tools and high-performance electronics.
Both materials have significant environmental and economic impacts, necessitating sustainable production and usage practices.
Advancements in technology continue to expand the applications and importance of graphite and diamond in various scientific and industrial fields.

Examiner Tip

Tips

Remember the "3D vs. Layered" concept: Diamond has a three-dimensional tetrahedral structure making it extremely hard and thermally conductive, whereas graphite's layered structure makes it slippery and electrically conductive.

Use mnemonics like "D for Diamond's Durability" and "G for Graphite's Glide" to recall their key properties and differences.

When studying applications, associate each material with its primary use: Diamond for cutting tools and jewelry, Graphite for pencils and lubricants.

Did You Know

1. Despite both being pure carbon, graphite and diamond have starkly different properties due to their distinct atomic arrangements. While graphite is soft and used in pencils, diamond is the hardest natural material known.

2. Synthetic diamonds are increasingly used in high-technology applications, including in advanced electronics and medical devices, beyond their traditional role in jewelry.

3. Graphene, a single layer of graphite, is one of the thinnest and strongest materials discovered, with potential applications in flexible electronics and nanotechnology.

Common Mistakes

Incorrect: Believing that all forms of carbon conduct electricity like graphite.
Correct: Only graphite conducts electricity due to its delocalized electrons; diamond does not conduct electricity.

Incorrect: Assuming that diamonds are naturally more abundant than graphite.
Correct: Graphite is more abundant and widely distributed in nature compared to diamonds.

Incorrect: Thinking that hardness in materials correlates directly with thermal conductivity.
Correct: While diamond is both hard and an excellent thermal conductor, hardness does not necessarily indicate thermal conductivity, as seen with graphite.

FAQ

What is the primary difference in the bonding between graphite and diamond?

Graphite has sp² hybridized carbon atoms forming planar layers with delocalized electrons, while diamond has sp³ hybridized carbon atoms creating a rigid three-dimensional tetrahedral network.

Why is graphite a good conductor of electricity?

Graphite's delocalized $\pi$ electrons within its layers allow electrons to move freely, facilitating electrical conductivity.

How does the structure of diamond contribute to its hardness?

Diamond's extensive sp³ covalent bonding forms a strong and rigid three-dimensional lattice, making it the hardest natural material.

Can graphite conduct heat effectively?

Graphite has moderate thermal conductivity due to the movement of electrons and lattice vibrations, but it is less effective compared to diamond.

In what applications is diamond used outside of jewelry?

Diamond is used in cutting tools, abrasives, heat sinks for electronics, optical components, and emerging technologies like quantum computing.

Why is diamond an electrical insulator?

Diamond lacks free-moving electrons because all its carbon atoms are tetrahedrally bonded, preventing electrical conduction.

1. Acids, Bases, and Salts

1.1 Salt Preparation

1.1.1 Making soluble salts by reaction with excess metal

1.1.2 Making soluble salts by reaction with excess base

1.1.3 Making soluble salts by reaction with excess carbonate

1.1.4 Making soluble salts by titration

1.2 Solubility Rules

1.2.1 Solubility of sodium, potassium, ammonium salts

1.2.2 Solubility of nitrates, chlorides, sulfates, carbonates, and hydroxides

1.3 Hydrated and Anhydrous Salts

1.3.1 Definition of hydrated and anhydrous substances

1.4 Insoluble Salts

1.4.1 Making insoluble salts by precipitation

1.5 Water of Crystallization

1.5.1 Definition and examples (CuSO₄·5H₂O, CoCl₂·6H₂O)

1.6 Properties of Acids

1.6.1 Reaction of acids with metals, bases, and carbonates

1.6.2 Effect of acids on litmus, thymolphthalein, and methyl orange

1.7 Properties of Bases

1.7.1 Definition of bases and alkalis

1.7.2 Reactions of bases with acids and ammonium salts

1.7.3 Effect of alkalis on litmus, thymolphthalein, and methyl orange

1.8 Acids and Alkalis in Aqueous Solution

1.8.1 H⁺ ions in acids, OH⁻ ions in alkalis

1.8.2 Compare acidity and alkalinity using pH and indicators

1.9 Neutralization

1.9.1 Reaction of acids with alkalis to form water

1.10 Strong and Weak Acids

1.10.1 Definition of strong and weak acids

1.10.2 Hydrochloric acid as a strong acid (HCl → H⁺ + Cl⁻)

1.10.3 Ethanoic acid as a weak acid (CH₃COOH ⇌ H⁺ + CH₃COO⁻)

1.11 Oxides

1.11.1 Classify oxides as acidic (e.g., SO₂, CO₂) or basic (e.g., CuO, CaO)

1.11.2 Definition and examples of amphoteric oxides (Al₂O₃, ZnO)

2. Experimental Techniques and Chemical Analysis

2.1 Identification of Ions and Gases

2.1.1 Test for nitrate (NO₃⁻) using aluminum and NaOH

2.1.2 Test for sulfite (SO₃²⁻) using acidified KMnO₄

2.1.3 Cation tests using NaOH and NH₃

2.1.4 Gas tests for NH₃, CO₂, Cl₂, H₂, O₂, SO₂

2.1.5 Flame tests for Li⁺, Na⁺, K⁺, Ca²⁺, Ba²⁺, Cu²⁺

2.1.6 Test for carbonate (CO₃²⁻) using acid

2.1.7 Test for halides (Cl⁻, Br⁻, I⁻) using silver nitrate

2.1.8 Test for sulfate (SO₄²⁻) using barium nitrate

2.2 Experimental Design

2.2.1 Measuring time, temperature, mass, volume

2.2.2 Advantages and disadvantages of methods

2.2.3 Definitions of solvent, solute, solution

2.2.4 Definition of saturated solution

2.2.5 Definition of residue and filtrate

2.3 Acid-Base Titrations

2.3.1 Titration procedure using burette and pipette

2.3.2 Identifying endpoint using indicators

2.4 Chromatography

2.4.1 Paper chromatography for separating mixtures

2.4.2 Identifying substances using chromatograms

2.4.3 Rf value calculation

2.5 Separation and Purification

2.5.1 Filtration, crystallization, distillation

2.5.2 Identifying purity using melting and boiling points

3. Chemical Reactions

3.1 Rate of Reaction

3.1.1 Collision theory: kinetic energy of particles

3.1.2 Collision theory: activation energy

3.1.3 How changes in conditions affect reaction rate

3.1.4 How catalysts lower activation energy

3.1.5 Effect of concentration on reaction rate

3.1.6 Effect of gas pressure on reaction rate

3.1.7 Effect of surface area on reaction rate

3.1.8 Effect of temperature on reaction rate

3.1.9 Effect of catalysts on reaction rate

3.1.10 Definition of catalyst and its role

3.1.11 Methods to measure reaction rate

3.1.12 Interpret graphs of reaction rates

3.1.13 Collision theory: particle concentration

3.1.14 Collision theory: frequency of collisions

3.2 Reversible Reactions and Equilibrium

3.2.1 Definition of reversible reactions

3.2.2 Effect of conditions on reaction direction

3.2.3 Definition of dynamic equilibrium

3.2.4 Effect of temperature on equilibrium

3.2.5 Effect of pressure on equilibrium

3.2.6 Effect of concentration on equilibrium

3.2.7 Effect of catalyst on equilibrium

3.2.8 Haber process equation (N₂ + 3H₂ ⇌ 2NH₃)

3.2.9 Raw materials for Haber process

3.2.10 Conditions used in Haber process

3.2.11 Contact process equation (2SO₂ + O₂ ⇌ 2SO₃)

3.2.12 Raw materials for Contact process

3.2.13 Conditions used in Contact process

3.2.14 Why contact process conditions are used

3.3 Redox

3.3.1 Definition of redox reactions

3.3.2 Oxidation as gain of oxygen, reduction as loss of oxygen

3.3.3 Identify redox reactions using oxygen gain/loss

3.3.4 Definition of oxidation and reduction in terms of electrons

3.3.5 Oxidation and reduction in terms of oxidation numbers

3.3.6 Redox reactions using color changes (MnO₄⁻, I₂)

3.3.7 Definition of oxidizing and reducing agents

3.3.8 Identify oxidizing and reducing agents in reactions

3.3.9 Use of oxidation numbers to identify redox reactions

3.4 Physical and Chemical Changes

3.4.1 Difference between physical and chemical changes

4. Metals

4.1 Corrosion of Metals

4.1.1 Barrier methods (painting, greasing, plastic coating)

4.1.2 How barriers prevent rust (oxygen/water exclusion)

4.1.3 Galvanizing with zinc as protection

4.1.4 Sacrificial protection using reactive metals

4.1.5 Conditions needed for rusting of iron

4.2 Extraction of Metals

4.2.1 Ease of metal extraction depends on reactivity

4.2.2 Blast furnace: iron extracted from hematite

4.2.3 Role of carbon and carbon monoxide in reduction

4.2.4 Thermal decomposition of limestone in furnace

4.2.5 Formation of slag (removes impurities)

4.2.6 Aluminium extraction from bauxite by electrolysis

4.2.7 Blast furnace equations: C + O₂ → CO₂, C + CO₂ → 2CO, Fe₂O₃ + 3CO → 2Fe + 3CO₂

4.2.8 Aluminium extraction: role of cryolite

4.2.9 Why carbon anodes must be replaced in aluminium extraction

4.2.10 Reactions at electrodes in aluminium extraction

4.3 Properties of Metals

4.3.1 Compare physical properties of metals and non-metals

4.3.2 Reactions of metals with acids, water, and oxygen

4.4 Uses of Metals

4.4.1 Uses of aluminium (aircraft, electrical cables, food containers)

4.4.2 Uses of copper (electrical wiring, ductility)

4.5 Alloys

4.5.1 Definition of alloys (mixture of metal with other elements)

4.5.2 Examples: brass (Cu + Zn), stainless steel (Fe + Cr + Ni + C)

4.5.3 Alloys are harder and stronger than pure metals

4.5.4 Why alloys are harder (atoms disrupt layers)

4.6 Reactivity Series

4.6.1 Order of reactivity: K, Na, Ca, Mg, Al, C, Zn, Fe, H, Cu, Ag, Au

4.6.2 Reactions of K, Na, Ca with water

4.6.3 Reaction of Mg with steam

4.6.4 Reactions of Mg, Zn, Fe, Cu, Ag, Au with acids

4.6.5 Explain reactivity based on ion formation

4.6.6 Displacement reactions of metals

4.6.7 Why aluminium appears unreactive (oxide layer)

5. Stoichiometry

5.1 Formulae

5.1.1 Definition of empirical formula

5.1.2 Deduce ionic formula from charges

5.1.3 Write balanced equations with state symbols

5.1.4 Formulae of elements and compounds

5.1.5 Determine formula from atomic ratios

5.1.6 Definition of molecular formula

5.1.7 Write word and symbol equations

5.2 Relative Masses

5.2.1 Definition of relative atomic mass (Ar)

5.2.2 Definition of relative molecular/formula mass (Mr)

5.2.3 Calculate reacting masses (without mole concept)

5.3 The Mole and Avogadro Constant

5.3.1 Concentration in g/dm³ and mol/dm³

5.3.2 Definition of the mole (6.02 × 10²³ particles)

5.3.3 Mole calculations using mass and molar mass

5.3.4 Use molar gas volume (24 dm³ at r.t.p.)

5.3.5 Calculate reacting masses and limiting reactants

5.3.6 Titration calculations (moles, volume, concentration)

5.3.7 Calculate empirical and molecular formulae

5.3.8 Calculate percentage yield and purity

6. Organic Chemistry

6.1 Formulae and Functional Groups

6.1.1 Definition of saturated and unsaturated compounds

6.1.2 Draw and interpret displayed formulae

6.1.3 General formulae for alkanes, alkenes, alcohols, carboxylic acids

6.1.4 Definition of functional groups

6.1.5 Definition of a homologous series

6.2 Naming Organic Compounds

6.2.1 Naming and drawing methane, ethane, ethene, ethanol, ethanoic acid

6.2.2 Identifying organic compounds based on name, formula, or structure

6.3 Fuels

6.3.1 Names of fossil fuels: coal, natural gas, petroleum

6.3.2 Methane as the main component of natural gas

6.3.3 Definition of hydrocarbons

6.3.4 Petroleum as a mixture of hydrocarbons

6.3.5 Fractional distillation of petroleum

6.3.6 Properties of fractions (volatility, boiling points, viscosity)

6.3.7 Uses of petroleum fractions (refinery gas, gasoline, naphtha, kerosene, diesel, fuel oil, lubricatin

6.4 Alkanes

6.4.1 Single covalent bonds in alkanes (saturated hydrocarbons)

6.4.2 Alkanes are generally unreactive except for combustion and substitution

6.5 Alkenes

6.5.1 Double carbon-carbon bonds in alkenes (unsaturated hydrocarbons)

6.5.2 Cracking of large alkanes to produce alkenes and hydrogen

6.5.3 Test for unsaturation using bromine water

6.6 Alcohols

6.6.1 Ethanol production by fermentation of glucose

6.6.2 Ethanol production by catalytic hydration of ethene

6.6.3 Combustion of ethanol

6.6.4 Uses of ethanol (solvent, fuel)

6.7 Carboxylic Acids

6.7.1 Reactions of ethanoic acid with metals, bases, and carbonates

6.7.2 Formation of ethanoic acid by oxidation of ethanol

6.7.3 Ester formation from carboxylic acids and alcohols

6.8 Polymers

6.8.1 Definition of polymers and monomers

6.8.2 Formation of poly(ethene) by addition polymerization

6.8.3 Plastics are made from polymers

6.8.4 Environmental issues of plastics (landfills, ocean waste, toxic gases)

7. States of Matter

7.1 Solids, Liquids, and Gases

7.1.1 Properties of solids, liquids, and gases

7.1.2 Particle arrangement in solids, liquids, and gases

7.1.3 Changes of state: melting, boiling, evaporation, freezing, condensation

7.1.4 Effect of temperature and pressure on gas volume

7.2 Diffusion

7.2.1 Diffusion explained using kinetic particle theory

8. The Periodic Table

8.1 Arrangement of Elements

8.1.1 Periodic Table arranged by atomic number

8.1.2 Change from metallic to non-metallic across a period

8.1.3 Relation of group number to ion charge

8.1.5 Predicting properties using Periodic Table position

8.2 Group I: Alkali Metals

8.2.1 Properties of lithium, sodium, and potassium

8.2.2 Trends down Group I: melting point, density, reactivity

8.2.3 Predict properties of other Group I elements

8.3 Group VII: Halogens

8.3.1 Properties of chlorine, bromine, iodine

8.3.2 Trends down Group VII: density, reactivity

8.3.3 Appearance of halogens at room temperature

8.3.4 Displacement reactions of halogens

8.3.5 Predict properties of other Group VII elements

8.4 Transition Elements

8.4.1 Properties: high density, melting points, colored compounds, catalysts

8.4.2 Variable oxidation states (iron(II) and iron(III))

8.5 Group VIII: Noble Gases

8.5.1 Noble gases are unreactive and monatomic

8.5.2 Explanation of noble gas stability using electron configuration

9. Atoms, Elements, and Compounds

9.1 Elements, Compounds, and Mixtures

9.1.1 Difference between elements, compounds, and mixtures

9.2 Atomic Structure

9.2.1 Structure of an atom (nucleus, electrons, shells)

9.2.2 Relative charges and masses of subatomic particles

9.2.3 Definition of atomic number (proton number)

9.2.4 Definition of mass number (nucleon number)

9.2.5 Electronic configuration for elements (1-20)

9.2.6 Full outer shell in noble gases (Group VIII)

9.2.7 Relation of outer electrons to group number

9.2.8 Relation of electron shells to period number

9.3 Isotopes

9.3.1 Definition of isotopes

9.3.2 Symbols of isotopes (e.g., ₆¹²C, ₁₇³⁵Cl⁻)

9.3.3 Why isotopes have the same chemical properties

9.3.4 Calculating relative atomic mass from isotopes

9.4 Ions and Ionic Bonds

9.4.1 Formation of cations and anions

9.4.2 Definition of ionic bonding

9.4.3 Formation of ionic bonds (dot-and-cross diagrams)

9.4.4 Properties of ionic compounds

9.4.5 Giant lattice structure in ionic compounds

9.5 Simple Molecules and Covalent Bonds

9.5.1 Definition of covalent bonding

9.5.2 Formation of simple covalent molecules (H₂, Cl₂, H₂O, CH₄, NH₃, HCl)

9.5.3 Properties of simple molecular compounds

9.5.4 Dot-and-cross diagrams for CH₃OH, C₂H₄, O₂, CO₂, N₂

9.6 Giant Covalent Structures

9.6.1 Structure of graphite and diamond

9.6.2 Uses of graphite and diamond

9.6.3 Structure of silicon(IV) oxide (SiO₂)

9.7 Metallic Bonding

9.7.1 Definition of metallic bonding

9.7.2 Properties of metals (conductivity, malleability, ductility)

10. Chemistry of the Environment

10.1 Water

10.1.1 Test for water using cobalt(II) chloride and copper(II) sulfate

10.1.2 Test for purity of water using melting and boiling points

10.1.3 Why distilled water is used in chemistry

10.1.4 Substances in natural water (oxygen, metals, plastics, sewage, microbes, fertilizers)

10.1.5 Harmful substances in water (toxins, nitrates, phosphates, microbes)

10.1.6 Water treatment: sedimentation and filtration

10.1.7 Water treatment: activated carbon for odor removal

10.1.8 Water treatment: chlorination to kill microbes

10.2 Fertilizers

10.2.1 Use of ammonium salts and nitrates as fertilizers

10.2.2 NPK fertilizers for nitrogen, phosphorus, potassium supply

10.3 Air Quality and Climate

10.3.1 Composition of clean, dry air (78% N₂, 21% O₂, trace gases)

10.3.2 Sources of CO₂ (fuel combustion), CO (incomplete combustion), CH₄ (decomposition, digestion)

10.3.3 Sources of NOx (car engines), SO₂ (fossil fuels)

10.3.4 Effects of CO₂ and CH₄ (global warming, climate change)

10.3.5 Effects of CO (toxic), particulates (respiratory issues)

10.3.6 Effects of NOx and SO₂ (acid rain, respiratory problems)

10.3.7 How CO₂ and CH₄ cause global warming (heat absorption)

10.3.8 Ways to reduce climate change (trees, hydrogen, renewables)

10.3.9 Reducing acid rain (catalytic converters, low-sulfur fuels, flue gas desulfurization)

10.3.10 Photosynthesis reaction: CO₂ + H₂O → glucose + O₂

10.3.11 Photosynthesis equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

10.3.12 How NOx forms in car engines

10.3.13 How catalytic converters remove NOx (2CO + 2NO → 2CO₂ + N₂)

11. Electrochemistry

11.1 Electrolysis

11.1.1 Definition of electrolysis

11.1.2 Identify anode, cathode, and electrolyte

11.1.3 Electrolysis of molten lead(II) bromide

11.1.4 Electrolysis of concentrated sodium chloride

11.1.5 Electrolysis of dilute sulfuric acid

11.1.6 Products formed at electrodes

11.1.7 Predict products of binary molten compounds

11.1.8 Purpose of electroplating

11.1.9 Process of electroplating metals

11.1.10 Charge transfer in electrolysis (electrons in external circuit)

11.1.11 Charge transfer in electrolysis (ions in electrolyte)

11.1.12 Electrolysis of aqueous copper(II) sulfate (graphite vs copper electrodes)

11.1.13 Predict products for electrolysis of halide solutions

11.1.14 Write ionic half-equations for anode and cathode reactions

11.2 Hydrogen–Oxygen Fuel Cells

11.2.1 Definition of hydrogen–oxygen fuel cell

11.2.2 Advantages and disadvantages of fuel cells vs gasoline engines

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Uses of Graphite and Diamond

Introduction