CHEMISTRY SYLLABUS OUTLINE - Syllacon Notes

1

CHEMISTRY SYLLABUS OUTLINE

(republished 2012 edition)

Note: SPECIAL THANKS to the following for pointing out

errors that were present in previous versions:

Mrs Felicia Wong and Pham Thang Loi (VS 4D 2011)

Lim Ting Jie

VS Class of 2011

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SECTION I: EXPERIMENTAL CHEMISTRY

1. Experimental Chemistry

Description Content Years tested

1.2 Methods of purification and analysis

(a) (ii) Sublimation

Inverted funnel with a wet cloth on the sides over the heated evaporating dish

Separates solid that is able to change its state to gas directly without becoming a liquid from solid that is unable to decompose when heated

-

(a) (iii) Distillation (and fractional distillation)

The liquid, with a lower boiling point, will boil to become a gas and pass through the Liebig condenser to be condensed and collected as liquid in the beaker

Separates liquid from the solid dissolved in it

(Separates liquids of differing boiling points that are misible with a fractionating column of glass beads)

2006^

(b) Paper chromatography

Spot of the mixture of different compounds is applied to pencil marking of paper, its end thereafter dipped in ethanol

Ethanol that is soaked up by the paper dissolves the dyes and carries them up the chromatography paper

More soluble dyes will be carried further up, higher Rf value

2007

SECTION II: ATOMIC STRUCTURE AND STOICHIOMETRY

2. The Particulate Nature of Matter


2.1 Kinetic particle theory

(a) (i) Solid state Closely packed in a regular pattern

Vibrate about fixed positions

2007

(a) (ii) Liquid state Closely packed in a disorderly manner

Move randomly and slide over one another

(a) (iii) Gaseous state Spread far apart in a disorderly manner

Move randomly and rapidly

(b) Evidence for movement of particles in fluids

Fluids have no fixed shape

Particles are not held in fixed positions

Have high kinetic energy and able to move about

-

(d) (i) Effect of molecular mass on the rate of diffusion

Gas A has a higher molecular mass than Gas B

Heavier than Gas B

Requires more energy to move it to another place

Diffuses at a slower rate

2003, 2010

(d) (ii) Effect of temperature on rate of diffusion

Gas A is at a higher temperature than Gas B

Posses greater kinetic energy than Gas B

Diffuses at a faster rate

-

2.3 Structure and properties of materials

(b) (i) Low mbps. of simple molecular subs.

Weak intermolecular forces between the molecules

Little energy needed to break them

2003, 2004, 2006^

(b) (ii) Inability to conduct electricity of simple molecular subs.

All electrons bonded in the neutral molecules

No mobile ions or electrons free to move in conduction

2003, 2008

(b) (iii) High melting and boiling points of tetrahedral giant molecular substances

Atoms held together by strong covalent bonds

Tetrahedral and three-dimensional network

Large amounts of energy needed to break strong bonds

2004

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(b) (iii) Inability to conduct electricity of tetrahedral giant molecular substances

Each atom covalently bonded to 4 other atoms

All electrons are used in bonding

No free mobile electrons able to move about to conduct electricity

-

(b) (iii) Hard and abrasive properties of tetrahedral giant molecular substances


Rigid structure of tetrahedral network

Large amounts of energy needed to distort arrangement

2004^

(b) (iv) High mbps of parallel giant molecular substances


Within their layers

Much energy needed to break strong bonds

-

(b) (iv) Ability to conduct electricity of parallel giant molecular substances

Each atom covalently bonded to 3 other atoms instead of 4

Each consists of an electron not used for bonding

Free to move about and conduct electricity

2008

(b) (iv) Lubricative property of parallel giant molecular substances

Carbon atoms in hexagonal layers

Layers held by weak van der Waal’s forces of attraction

Small amount of energy needed for layers to slide past one other

-

2.4 Ionic bonding

(e) High melting and boiling points of ionic compounds

Giant lattice network of positive and negative ions

Strong electrostatic forces of attraction

Large amounts of energy needed to overcome

2002, 2006

(e) Electrical conductivity of ionic compounds

Giant lattice network of positive and negative ions

Strong electrostatic forces of attraction

Ions held strongly in fixed positions

Not free to move about during conducting

2006^

(e) Electrical conductivity of ionic compounds as when molten (or aqueous)

Original giant lattice structure when solid collapses

Ions not held strongly in fixed positions any longer

Free to move about during conducting of electricity

2006^, 2007

2.6 Metallic bonding

(b) Electrical conductivity of metals to the structure

Sea of delocalised valence electrons are mobile

Free to move from negative terminal to positive terminal in electrical circuit

2003, 2006^

SECTION IV: PERIODICITY

8. The Periodic Table


(a) Group I metals decreases in melting point (and increases in reactivity) with water down the group

Bigger atomic size

Outershell electron further away from nucleus

Less energy needed to break the weaker electrostatic force of attraction metallic bond between outershell electron and positive nuclei

(Easier to lose an electron)

-

(b) (i) Group VII halogens changes in state from gas to solid downwards

Molecular size increases

Stronger intermolecular forces of attraction

More energy needed to break the forces

Higher melting (liquid-solid) and boiling (gas-liquid) points

-

(b) (ii) Group VII halogens decrease in displacement reactivity with other halide ion solutions downwards

Bigger atomic size

Outershell electron further away from nucleus

Weaker electrostatic force of attraction to nucleus

Harder to gain an electron

2002

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SECTION III: CHEMISTRY OF REACTIONS

4. Electrolysis


(c) Electrolysis of molten sodium chloride (as an example)

Positive metal ion discharged and attracted to negative cathode

Metal atoms form a (white) metallic coating around the cathode

Negative ion discharged and attracted to positive anode

The (yellowish green) gas is formed

2004

(e) (i) (a) Selective discharge of cations in dilute electrolytes

Cation in the electrolyte is lower in the reactivity series than hydrogen ion of water

Less reactive

Preferentially discharged instead of hydrogen ion

Intensity of colour of electrolyte decreases and turns lighter (in cases of transition metals)

2009

(e) (i) (b) Selective discharge of cations in concentrated electrolytes

Cation in the electrolyte is lower in the reactivity series than carbon (of inert electrode)

Less reactive

Preferentially discharged instead of hydrogen ion

Intensity of colour of electrolyte decreases and turns lighter (in cases of transition metals)

-

(e) (ii) Selective discharge of cations in concentrated electrolytes

The non-polyatomic ion in the electrolyte is more reactive than hydroxide ion of water

Easier to be discharged and preferentially discharged instead

As hydrogen ions become greater in concentration than hydroxide ions,

Electrolyte turns more acidic

(e) (iii) (a) Selective discharge of hydrogen ions in dilute electrolytes

Hydrogen ion of the water is lower in the reactivity series than cation in the electrolyte

Less reactive and preferentially discharged instead of the cation

As hydroxide ions become greater in concentration than hydrogen ions,

Electrolyte turns more alkaline

-

(e) (iii) (b) Selective discharge of hydroxide ions in dilute electrolytes

Hydroxide ion is found in greater concentrations than anion in the electrolyte

Easier to be discharged and preferentially discharged instead

As hydrogen ions become greater in concentration than hydroxide ions,

Electrolyte turns more acidic

-

(i) Electroplating of metals and uses

Depositing a layer of metal on another substance using electrolysis

Make a cheap metal look more expensive with silver or gold

Protect a metallic object from corrosion with tin or chrome

-

(j) Electrical energy from redox reactions of simple cells

Oxidation occurs at less reactive electrode and reduction occurs at the more reactive electrode

Electrons are transferred from the more reactive electrode to the less reactive through the wire

These moving electrons in the external circuit constitute electric current

2008^

(j) Differences of electrical energy with different metals

Metal A is further away from Metal B in the reactivity series than it is from Metal C

Difference in their reactivities is higher

Greater voltage produced

2004

(k) Possible changes in electrolytes

Decrease in intensity of colour of aqueous salt in electrolyte

Changes in pH value

Changes in colour of solution by discharge of negative ions to form liquid

Metallic coating present at the cathode

Volume of molten electrolyte

2003, 2008

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5. Energy from Chemicals


(d) (i) Enthalpy changes in exothermic reactions

Heat energy released in covalent bond forming of Product B is greater than that absorbed in covalent bond breaking of the Reactant A

Moles of products and types of bonds included

2002

(d) (ii) Enthalpy changes in a endothermic reaction

Heat energy absorbed in covalent bond breaking of the Reactant A is greater than that released in covalent bond forming of Product B

Moles of products and types of bonds included

2009

(e) (i) Hydrogen and oxygen to generate electricity in a fuel cell

At positive cathode, oxygen gas is reduced to form hydroxide ions

At negative anode, hydrogen gas is oxidised to form water

The flow of electrons constitute electric current generating electricity

2009

Cathode Anode Overall

O2 + 2 H2O + 4e → 4 OH- 2 H2 + 4 OH- → 4 H2O + 4e O2 + 2 H2 → 2 H2O

(e) Hydrogen a potential fuel

Renewable source of energy and pollution free, water only product

But costly to obtain pure hydrogen and difficult to store

Also, less energy per volume than petrol

-

6. Chemical Reactions

Description Content Tested

6.1 Speed of reaction

(a) (i) Decreased concentration decreases rates of reactions

Particles A are further apart from one another

Less reactant particles per unit volume

Collisions between Particles A and B occur at a less frequent rate, resulting in less effective collisions

2003

(a) (ii) Increased pressure increases rates of reactions

Total volume of gas decreases

Particles A are squeezed closer together

More reactant particles per unit volume

Collisions between Particles A and B occur at a more frequent rate, resulting in more effective collisions

2002

(a) (iii) Decreased particle size increases rates of reactions

Higher surface area of Particles A are exposed to that of Particles B

Likelihood of collision of Particles A and B increases


2007

(a) (iv) Increased temperature increases rates of reactions

Higher kinetic energy is resulted in the Particles A

Particles A are move faster


-

(b) Effects of catalysts

Increases (alters) rate of a chemical reaction without itself being chemically changed and without any change in mass

-

(c) Pathways with lower activation energies

Catalysts provide an alternate reaction pathway with lower activation energy compared to the original reaction

More reacting particles can overcome the activation energy for reaction per unit time

2006, 2010

(e) Method for investigating effect of given variables

Using an electronic balance, cotton wool and conical flask for mass loss

Using a calibrated gas syringe, stopper and conical flask for increase in specific gases

2003, 2007, 2010

Note: You must state the names of the particles.

Ionic compounds can be either soluble or insoluble.

If soluble we refer to the particles as <name> ions,

but if insoluble we refer to them as, simply, <name> particles.

covalent bonding referred as <name> molecules.

metallic bonding referred as <name> metal atoms.

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7. Acids, Bases and Salts


7.1 Acids and bases

(c) (i) Strong and weak acids

Strong acids ionise fully in water to produce a high concentration of hydrogen ions irreversibly

Weak acids ionise partially in water to product a low concentration of hydrogen reversibly

2004, 2008, 2010^

(c) (ii) Comparing strong acids

Hydrochloric acid is monobasic while sulfuric acid is dibasic

Sulfuric acid has one more hydrogen atom replaceable by a metal than hydrochloric acid

Ionises more fully in water and reacts faster with reactants

2005

(g) Control of soil pH with calcium hydroxide

Calcium hydroxide is alkaline and react with acids to neutralise excess acidity by acid rain in soil

Excessive liming with result in excess alkalinity

React with ammonium fertilisers to form ammonia gas resulting in loss of nitrogen, a nutrient element essential for plant growth

2005, 2007^, 2009

7.2 Salts

(a) (i) Reactions with acids to prepare soluble salts (due to anion)

React acid with excess insoluble reactant

Filter the resulting solution to obtain filtrate containing the soluble salt in beaker

Heat the filtrate until saturated and allow it to cool

Wash with little cold distilled water and dry between pieces of filter paper

2004

(a) (iii) Pre-titration to prepare Group I/ammonium salts (cation)

Pipette 25 cm3 of alkali into the conical flask

Add a few drops of methyl orange

Titrate acid from burette into the beaker drop wise until solution turns from yellow to orange.

Note difference in initial and final reading of burette as X

-

(a) (iii) Main titration to prepare Group I/ammonium salts (cation)

Pipette 25 cm3 of alkali into a beaker

Titrate X volume of acid into it

Heat the filtrate until saturated and allow it to cool

Wash with little cold distilled water and dry between pieces of filter paper

2004

(a) (ii) Precipitation to prepare insoluble salts

React the aqueous solutions together

Filter the resulting solution to obtain residue in the filter paper

Wash with much distilled water and dry between pieces of filter paper

2004^

(i) (i) Acidic oxides

Contains an non-metal (usually forming a dioxide or higher with oxygen e.g. SO2)

Can react with alkali to form a salt and water to form an acid

-

(i) (ii) Amp-hoteric oxides

Oxides of Zn, Al, Pb (ZAP)

Can react with both acids and alkalis to form salt and water -

(i) (iii) Basic oxides

‘Metal oxides that are not amphotheric’

Can react with acid to form a salt and water if soluble to form an alkali

2010

(i) (iv) Neutral oxides

Contains an non-metal (usually forming a monoxide with oxygen e.g. H2O)

Unable to react with acids nor alkalis

-

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9. Metals


9.1 Properties of metals

(a) (i) High mbps of metals that are not from Group I

Strong electrostatic force of attraction between positive ions and delocalised sea of electrons.

Large amount of energy is needed to break the strong metallic bonds

2003^

(a) (ii) Physical property of metals as being malleable

Equally sized atoms are orderly arranged.

Each electron does not belong to any particular ion

Metallic bonds will not be broken if positive metal ions are displaced

Applied force can cause layers to slide over each other easily

2003^

(a) (iii) Metals are good conductors of heat

Sea of delocalised valance electrons are mobile

Free to move rapidly across metal surface

Carrying heat energy with it at the same time

-

(a) (iv) Metals are good conductors of electricity

Sea of delocalised valence electrons are mobile

Free to move from negative terminal to positive terminal in electrical circuit

2003, 2005

(d) Alloys have different physical properties to their constituent elements

Alloys are harder than the constituent element

Atoms of another element added have a different size from that of the pure metal

Regular arrangement of atoms in the pure metal is disrupted

Atoms of differing sizes cannot slide over one another as easily as before

2007, 2010

9.3 Extraction of metals

(a) (i) Ease of obtaining metals from CO3

2- and OH- ores

Only carbonates/hydroxides of metals of lower reactivities between Calcium and Copper in the reactivity series can decompose to form its metal oxides

Carbonates of metals of higher reactivities are more thermally stable and hence does not decompose

2002

(a) (ii) Ease of obtaining metals from oxide ores

Only oxides of metals of lower reactivities between Mercury and Platinum in the reactivity series can decompose to form their respective metals

Oxides of metals of higher reactivities are more thermally stable and hence does not decompose

-

(a) (iii) Ease of obtaining metals from decomposition of their compounds in general

Metal A in metal oxide/carbonate A is more reactive than Metal B in metal oxide/carbonate B

It is more thermally stable hence more difficult for Metal A to be extracted from its oxide/carbonate by decomposition compared to Metal B

Rate of decomposition is slower

2004, 2010^

9.4 Recycling of metals

(a) Metals need to be recycled

Metal ores are finite resources

Recycling will decrease the space needed for landfills required to dispose metals, hence decreasing land pollution

2002, 2004

9.5 Iron

(d) Prevention of rusting to be achieved

Painting, plastic coating, greasing, galvanising (zinc-plating)

Protective layer of substance

Prevents water and air from coming into contact with surface

Not all conditions for rusting present

2005^, 2007

(e) Sacrificial protection of a metal by a more reactive metal

Metal A is higher in reactivity series

More reactive and loses electrons more readily than Metal B

Oxidised by air and water in preference to Metal B

Metal B offers sacrificial protection to other metal and hence corrodes preferentially

2002, 2006

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SECTION V: ATMOSPHERE

10. Air


(c) (i) state the source of carbon monoxide

Incomplete combustion under limited oxygen supply

Carbon-containing substances like petroleum

Forms instead of carbon dioxide in complete combustion

2009

(c) (ii) state the source of nitrogen oxides

High temperatures from lightning activity and internal combustion engines

Provide enough energy to break the triple covalent bonds between nitrogen atoms of nitrogen gas in air

Each nitrogen atom reacts with oxygen

-

(c) (iii) state the source of sulfur dioxide

Volcanic eruptions and

Combustion of fossil fuels form sulfur gas

Sulfur atoms react with oxygen

-

(d) (i) describe solutions to problems from carbon monoxide and nitrogen monoxide

Catalytic converters

Platinum and rhodium catalysts

Less or non harmful carbon dioxide and nitrogen gas

By redox reactions

-

(d) (ii) describe solutions to problems from unburnt hydrocarbons

Catalytic converters of platinum and rhodium catalysts

Less or non harmful carbon dioxide and water vapour

By redox reactions

2004^

(d) (iii) describe solutions to problems from sulfur dioxide

Flue gas desulfurisation plant

Calcium carbonate reacts with sulfur dioxide to form calcium sulfite and carbon dioxide gas

Calcium sulfite oxidised by oxygen in air to form calcium sulfate

-

(e) (i) discuss effects of carbon monoxide

Reacts more readily with haemoglobin of red blood cells than oxygen does

Stable carboxyhaemoglobin compound forms

Red blood cells unable to transport blood around body efficiently

Dizziness and death likely to result

2002, 2004, 2010

(e) (ii) discuss effects of nitrogen oxides and sulfur dioxide

High levels will cause inflammation of lungs, bronchitis

Dissolve in rainwater and oxidise in air to form nitric and sulfuric acids in rain

Vegetation soil leached and marine habitats polluted

Corrodes buildings made of metal and carbonates

2006^, 2010

(f) (i) discuss importance of the ozone layer

Filter UV radiation

Genetic mutations causing eye cataracts and skin cancer

Harm to marine life

2002, 2006

(f) (ii) discuss problems involved with the depletion of ozone

Aerosol propellants that force out contents and coolants in refrigerators expel chlorofluorocarbons

Stable and diffuse in air easily

React with ozone under sunlight

2006^

(h) give the sources of carbon dioxide

Respiration of organisms

Combustion of carbon-containing fuels -

(h) give the sources of methane

Bacterial decomposition and decay of vegetation, animals and rubbish

2007

(h) discuss possible consequences of global warming

Higher temperatures will melt icebergs at the North and South poles, flooding lowlands and coastal areas

Decreases crop yields with droughts in dry countries from higher temperatures

2002, 2007, 2010

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SECTION VI: ORGANIC CHEMISTRY

11. Organic Chemistry


11.1 Fuels and crude oil

(b) Fractional distillation of petroleum

Petroleum heated into a vapour is pumped into fractionating column

Hot vapour rises up and cools

Larger hydrocarbons of higher boiling points condense lower in the column, while smaller ones of lower boiling points condense higher in the column

2004

(e) Issues of competing uses of oil as an energy source and as a chemical feedstock

Petroleum in a non-renewable energy source.

Hydrocarbons when combusted produces greenhouse gas carbon dioxide causing global warming

Sulfur dioxide from coal and petroleum causes acid rain and soot is also produced

-

11.2 Alkanes

(a) (i) Homologous series

Group of organic compounds with a general formula of ____

Similar chemical properties differing only by CH2 units

2009, 2010

(a) (ii) Increase in melting and boiling points

Increase in molecular size and mass

Intermolecular forces between molecules increase

More energy required to break the forces

2005^, 2006

(a) (iii) Increase in viscosity


Intermolecular forces between molecules increase

Flows less easily and more resistant to flow

-

(a) (iv) Gradation in flammability (less) and sootiness (more)


Higher percentage of carbon

Less flammable and harder to burn

Smokier and sootier flame

-

11.3 Alkenes

(c) Purpose of cracking

Match the higher demand for fractions containing shorter chained hydrocarbon as smaller molecules from the refinery process

11.5: Carboxylic acids

(f) Commercial uses of esters

Perfumes (sweet and fruity, colourless and insoluble)

Flavourings (soluble in organic solvents)

Solvents (soluble in organic solvents)

2010

11.6 Macromolecules

(a) (i) Macromolecules

Large molecules built up from small units by covalent bonds

Different macromolecules having different units and/or different linkages

2009

(a) (ii) Monomers and polymers

A small molecule that can be joined together to form a large molecule known as a polymer

A long-chain molecule made up of many small molecules, known as monomers, joined together

2009, 2010

(a) (iii) Addition and condensation polymersation

Process of joining together monomer units to form a macromolecule

A - Without losing any molecules or atoms

C - With a small molecule as a by-product

2007, 2008

(f) Typical uses of man-made fibres

Clothing, parachutes, fishing line, sleeping bags

Easier to wash and dry

Long lasting as they do not shrink or crease

2005

(g) Problems by disposal of non-biodegradable plastics

Non-biodegradable plastics being long lasting (hence high in demand) cannot be decomposed by bacteria

Pollution by permanently being present at landfills

More space needed for landfills

2005^, 2008

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CONTENT W/O KEY WORDS OVERVIEW (refer to Chem Syllabus Quick References)

SECTION I: EXPERIMENTAL CHEMISTRY

1. Experimental Chemistry

1.1 Experimental design

(b) suggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of

gases and measurement of rates of reaction

1.2 Methods of purification and analysis

(a) describe methods of separations and purification

(i) use of a suitable solvent, filtration and crystallisation or evaporation

(b) (ii) interpret chromatograms including comparison with ‘known’ samples and the use of Rf values

(d) deduce from the given melting point and boiling point the identities of substances and their purity

(e) explain that the measurement of purity in substances used in everyday life, e.g. foodstuffs and drugs, is

important

1.3 Identification of ions and gases

(a) describe the use of aqueous sodium hydroxide and aqueous ammonia to identify the aqueous cations SAPAZCLCII

(b) describe tests to identify the anions NCSCI

(c) describe tests to identify the gases ACSCHO

SECTION II: ATOMIC STRUCTURE AND STOICHIOMETRY

2. The Particulate Nature of Matter

2.2 Atomic structure

(a) state the relative charges and approximate relative masses of a proton, a neutron and an electron

(b) describe, with the aid of diagrams, the structure of an atom as containing protons and neutrons (nucleons) in the

nucleus and electrons arranged in shells (energy levels)

(c) define proton (atomic) number and nucleon (mass) number

(e) define the term isotopes

(f) deduce the numbers of protons, neutrons and electrons in atoms and ions given proton and nucleon numbers


(a) describe the differences between elements, compounds and mixtures

(b) name some simple molecular substances, e.g. methane; iodine and giant molecular substances, e.g. poly(ethene);

sand (silicon dioxide); diamond; graphite

(d) deduce the physical and chemical properties of substances from their structures and bonding and vice versa

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2.4 Ionic bonding

(a) describe the formation of ions by electron loss/gain in order to obtain the electronic configuration of a noble gas

(b) describe the formation of ionic bonds between metals and non-metals, e.g. NaCl; MgCl2

(c) state that ionic materials contain a giant lattice in which the ions are held by electrostatic attraction, e.g. NaCl

(d) deduce the formulae of other ionic compounds from diagrams of their lattice structures, limited to binary

compounds

2.5 Covalent bonding

(a) describe the formation of a covalent bond by the sharing of a pair of electrons in order to gain the electronic

configuration of a noble gas

(b) describe, using ‘dot-and-cross’ diagrams, the formation of covalent bonds between nonmetallic elements, e.g. H2;

O2; H2O; CH4; CO2

(c) deduce the arrangement of electrons in other covalent molecules

2.6 Metallic bonding

(a) describe metals as a lattice of positive ions in a ‘sea of electrons’

3. Formulae, Stoichiometry and the Mole Concept

(a) state the symbols of the elements and formulae of the compounds mentioned in the syllabus

(b) deduce the formulae of simple compounds from the relative numbers of atoms present and vice versa

(c) deduce the formulae of ionic compounds from the charges on the ions present and vice versa

(d) interpret chemical equations with state symbols

(e) construct chemical equations, with state symbols, including ionic equations

(f) define relative atomic mass, Ar

(g) define relative molecular mass, Mr, and calculate relative molecular mass (and relative formula mass) as the sum

of relative atomic masses

(h) calculate the percentage mass of an element in a compound when given appropriate information

(i) calculate empirical and molecular formulae from relevant data

(j) calculate stoichiometric reacting masses and volumes of gases (one mole of gas occupies 24 dm3) at room

temperature and pressure); calculations involving the idea of limiting reactants may be set

(k) apply the concept of solution concentration (in mol/dm3 or g/dm3) to process the results of volumetric

experiments and to solve simple problems

(l) calculate % yield and % purity

12

SECTION III: CHEMISTRY OF REACTIONS

4. Electrolysis

(a) describe electrolysis as the conduction of electricity by an ionic compound (an electrolyte), when molten or

dissolved in water, leading to the decomposition of the electrolyte

(b) describe electrolysis as evidence for the existence of ions which are held in a lattice when solid but which are free

to move when molten or in solution

(g) construct ionic equations for the reactions occurring at the electrodes during the electrolysis, given relevant

information

5. Energy from Chemicals

(a) describe the meaning of enthalpy change in terms of exothermic (ΔH negative) and endothermic (ΔH positive)

reactions

(b) represent energy changes by energy profile diagrams, including reaction enthalpy changes and activation

energies (see 6.1(c),6.1(d))

6. Chemical Reactions

6.1 Speed of reaction

(d) state that some compounds act as catalysts in a range of industrial processes and that enzymes are biological

catalysts

(f) interpret data obtained from experiments concerned with speed of reaction

6.2 Redox

(a) define oxidation and reduction (redox) in terms of oxygen/hydrogen gain/loss

(b) define redox in terms of electron transfer and changes in oxidation state

(c) identify redox reactions in terms of oxygen/hydrogen gain/loss, electron gain/loss and changes in oxidation state

(d) describe the use of aqueous potassium iodide and acidified potassium dichromate(VI) in testing for oxidising and

reducing agents from the resulting colour changes

7. Acids, Bases and Salts

7.1 Acids and bases

(a) describe the meanings of the terms acid and alkali in terms of the ions they produce in aqueous solution and their

effects on Universal Indicator

(b) describe how to test hydrogen ion concentration and hence relative acidity using Universal Indicator and the pH

scale

(d) describe the characteristic properties of acids as in reactions with metals, bases and carbonates

(e) state the uses of sulfuric acid in the manufacture of detergents and fertilisers; and as a battery acid

(f) describe the reaction between hydrogen ions and hydroxide ions to produce water, H+ + OH- → H2O, as

neutralisation

13

(h) describe the characteristic properties of bases in reactions with acids and with ammonium salts

(j) classify sulfur dioxide as an acidic oxide and state its uses as a bleach, in the manufacture of wood pulp for paper

and as a food preservative (by killing bacteria)

7.2 Salts

(b) describe the general rules of solubility for common salts to include nitrates, chlorides (including silver and lead),

sulfates (including barium, calcium and lead), carbonates, hydroxides, Group I cations and ammonium salts

7.3 Ammonia

(a) describe the use of nitrogen, from air, and hydrogen, from cracking oil, in the manufacture of ammonia

(b) state that some chemical reactions are reversible, e.g. manufacture of ammonia

(c) describe the essential conditions for the manufacture of ammonia by the Haber process

(d) describe the displacement of ammonia from its salts


8. The Periodic Table

8.1 Periodic trends

(a) describe the Periodic Table as an arrangement of the elements in the order of increasing proton (atomic) number

(b) describe how the position of an element in the Periodic Table is related to proton number and electronic

structure

(c) describe the relationship between group number and the ionic charge of an element

(d) explain the similarities between the elements in the same group of the Periodic Table in terms of their electronic

structure

(e) describe the change from metallic to non-metallic character from left to right across a period of the Period Table

(f) describe the relationship between group number, number of valency electrons and metallic/non-metallic

character

(g) predict the properties of elements in Group I and VII using the Periodic Table

8.2 Group properties

(a) describe lithium, sodium and potassium in Group I (the alkali metals) as a collection of relatively soft, low density

metals

(b) describe chlorine, bromine and iodine in Group VII (the halogens) as a collection of diatomic non-metals

(c) describe the elements in Group 0 (the noble gases) as a collection of monatomic elements that are chemically

unreactive and hence important in providing an inert atmosphere, e.g. argon and neon in light bulbs; helium in

balloons; argon in the manufacture of steel

(d) describe the lack of reactivity of the noble gases in terms of their electronic structures

14

9. Metals

9.1 Properties of metals

(b) describe alloys as a mixture of a metal with another element, e.g. brass; stainless steel

(c) identify representations of metals and alloys from diagrams of structures

9.2 Reactivity series

(a) place in order of reactivity calcium, copper, (hydrogen), iron, lead, magnesium, potassium, silver, sodium and zinc

by reference to their reactions (SAW) and the reduction of their oxides (CH)

(b) describe the reactivity series as related to the tendency of a metal to form its positive ion, illustrated by its

reaction with the aqueous ions and/or oxides of the other listed metals

(c) deduce the order of reactivity from a given set of experimental results

(d) describe the action of heat on the carbonates of the listed metals and relate thermal stability to the reactivity

series

9.4 Recycling of metals

(b) discuss the social, economic and environmental issues of recycling metals

9.5 Iron

(a) describe and explain the essential reactions in the extraction of iron using haematite, limestone and coke in the

blast furnace

(b) describe steels as alloys which are a mixture of iron with carbon or other metals and how controlled use of these

additives changes the properties of the iron, e.g. high carbon steels are strong but brittle whereas low carbon steels

are softer and more easily shaped

(c) state the uses of mild steel, e.g. car bodies; machinery, and stainless steel, e.g. chemical plants; cutlery; surgical

instruments

SECTION V: ATMOSPHERE

10. Air

(a) describe the volume composition of gases present in dry air as being approximately 79% nitrogen, 20% oxygen

and the remainder being noble gases (with argon as the main constituent) and carbon dioxide

(b) name some common atmospheric pollutants, e.g. carbon monoxide; methane; nitrogen oxides (NO and NO2);

ozone; sulfur dioxide; unburned hydrocarbons

(g) describe the carbon cycle in simple terms, to include

(i) the processes of combustion, respiration and photosynthesis

(ii) how the carbon cycle regulates the amount of carbon dioxide in the atmosphere

15

SECTION VI: ORGANIC CHEMISTRY

11. Organic Chemistry (excluding key reactions and drawing of the four main structure types)

11.1 Fuels and crude oil

(a) name natural gas, mainly methane, and petroleum as sources of energy

(b) describe petroleum as a mixture of hydrocarbons and its separation into useful fractions by fractional distillation

(c) name the following fractions and state their uses

(i) petrol (gasoline) as a fuel in cars (iv) diesel as a fuel for diesel engines

(ii) naphtha as feedstock for the chemical industry

(iii) paraffin (kerosene) as a fuel for heating and cooking and for aircraft engines

(v) lubricating oils as lubricants and as a sources of polishes and waxes (vi) bitumen for making road surfaces

(d) state that the naphtha fraction from crude oil is the main source of hydrocarbons used as the feedstock for the

production of a wide range of organic compounds

11.2 Alkanes

(d) define isomerism and identify isomers

(e) describe the properties of alkanes (exemplified by methane) as being generally unreactive

11.3 Alkenes

(a) describe the alkenes as an homologous series of unsaturated hydrocarbons

(c) recognise that cracking is essential to match the demand for fractions containing smaller molecules from the

refinery process

(d) describe the difference between saturated and unsaturated hydrocarbons from their molecular structures

(f) state the meaning of polyunsaturated when applied to food products

11.4 Alcohols

(e) state some uses of ethanol, e.g. as a solvent; as a fuel; as a constituent of alcoholic beverages

11.5 Carboxylic acids

(c) describe the carboxylic acids as weak acids, reacting with carbonates, bases and some metals

11.6 Macromolecules

(b) describe the formation of poly(ethene) as an example of addition polymerisation of ethene as the monomer

(c) state some uses of poly(ethene) as a typical plastic, e.g. plastic bags; clingfilm

(d) deduce the structure of the polymer product from a given monomer and vice versa

(e) describe nylon, a polyamide, and Terylene, a polyester, as condensation polymers, the partial structure of nylon

being represented and the partial structure of Terylene

Documents

CHEMISTRY SYLLABUS OUTLINE - Syllacon Notes