Checklist Chemistry 2009 Yvonne

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Yvonne Choo Shuen Lann

Chapter 2: Structure of the Atom

A. Knowledge (Definition, meaning and facts)

Atom

- Smallest particle that can participate in chemical reaction.

Molecule

- Group of 2 or more atoms which are chemically bonded together.

Ion

- Charged particle.

Melting Point

- The temperature that remains constant at which a solid changes into a liquid at a particular

pressure.

Boiling Point

- The temperature that remains constant at which a liquid changes into a gas at a particular

pressure.

Proton Number

- The number of proton presence in an atom.

Nucleon Number

- The total number of proton and neutron in an atom.

Isotopes

- Atoms of the same element with the same number of proton but different number of

neutrons.

Uses of Isotopes

- Sodium-24: Detect leak in pipes carrying gas

- Cobalt-60: Radiotherapy for treating cancer

- Gamma rays of Cobalt-60: Destroy bacteria in food where the food quality doesnt change

- Phosphorous-32: Fertilizers & to study metabolism of Phosphorous in plants

- Carbon-14: Carbon dating (estimate age of fossils and artefacts)



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B) § nd ¨ © st nding/ Appli tion/ Analysis

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Why the temperature remains unchanged during f reezing?

- T 0 1 s 1 s 2 ec 3 4 se5

0 e 0 e 3

5

6 7 ss5

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5

0 e s 4 8 8 7 4 9 @ 1 9

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Solid Changed into Gas (The Full Process)?

- WheF G

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s he G

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heyb

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y changeQ

P nto liquid. In liquid form, the particles have a higher amount of kinetic energy than it is in

solid and they can move in a more random manner. When it reaches the boiling point, the particles can move freely and in a random manner as it has changed its state into gas which

has the highest kinetic energy and the weakest force of attraction between particles.

Solid Liquid c as

- Low Kinetic Energy - Kinetic Energy is lower

than it is in solid and

higher than gas

- Low Kinetic Energy

- High Force of attraction

between particles

- Force of attraction

between particles are

as strong as it is in solid

- Low Force of attraction

between particles

- d articles are arranged

in orderly manner.

- e otate and vibrate at

fixed position only.

- d articles are closely

packed together but

can move in a random

manner.

- d articles can move

freely and randomly.

Main Subatomic Particles of an Atom

Subatomic Particles Relative Atomic Mass Relative Charge

Proton 1 +1

Neutron 1 0

Electron 0.0005 -1



Y v f g g

e h

i

f f

p

i

q eg

Lr g g

a)Neutron number = 14

b)

C) Synthesis (Experiment)

Solid Z has a melting point of 65Cs Describe a laboratory experiment to determine the melting

point of Z.

1. t

boiling tube is filled with solid Z to a depth of 3cm and a thermometer is put into it.

2. The boiling tube is suspended in a beaker half -filled with water using a retort stand and

clamp. The level of solid Z in the boiling tube must be below the level of water in the beaker.

3. The water is heated and the solid Z is stirred slowly with the thermometer. When the

temperature of the solid Z reaches 45C, the stopwatch is started.

4. The temperature and the state of substance Z is recorded at half minute intervals until the

temperature of substance Z reaches 80C.

Compound W has a f reezing point of 82C. Describe a laboratory experiment to determinethe

f reezing point of W.

1. Step 1 to 2 of the above experiment is repeated using compound W instead.

2. The water is heated and the compound W is stirred slowly with the thermometer. When

compound W reaches 95C, the heating is stopped.

3. The boiling tube is removed from the water bath and the outer surface is dried up. Then it is

immediately put into a conical flask with half of the top of the boiling tube clamped using a

retort stand. The compound W is stirred continuously.

4. The temperature and the state of compound W is recorded at half -minute intervals until the

temperature drops to about 75C.

(*Diagrams ref er to appendix u




Chapter 3: Chemical Formulae and Equations


Relativ

e atomic mass (RAM)

- Number of times the mass of an atom is greater than 1/12 times of the mass of a carbon-12

atom. The relative mass of carbon-12 atom is 12.000.

Mole

- An amount of substance that contains as many particle as the number of atoms in ew

actly

12g of carbon-12.

Ax

ogadro Constant NA

- Number of particles in one mole of substance of unitsy molecules or atoms.

Molar Mass

- Mass of 1mol of substance mass of NA (no. of particles) mass of 6.02

1023

.

Molar Volume

- The volume occupied by one mole of gas.

Chemical Formulae

- The representation of a chemical substance by using letters for atoms and subscript number

to show the number of each type of atoms that are present in the substance.

Empirical Formulae

- The formula that shows the simplest whole number ratio of atoms of each element in the

compound.

Molecular Formulae

- The formula that shows the actual number of atoms of each element that is present in a

molecule of the compound.

- Molecular formula = (empirical formula)n

Structural Formula

- A formula that shows how atoms are bonded together with covalent bonds in a molecule of

a compound.

Chemical equation

- The shorthand description of a chemical reaction.



Y v

e

e

L

B) nderstanding/ Application/ Analysis

Why empirical formula of copper (

) oxide cannot be determined by heating copper po

der in a

crucible?

- This is because copper is not a reactive metal so it will take a long time for it to react with

the oxygen in air. Thus, to determine the empirical formula of copper (II) oxide, another

method is used. The method uses continuous flowing hydrogen gas to obtain copper metal

from the reduction of copper (II) oxide.

Compare and Contrast

Ethane

Empirical Formula Molecular Formula

CH3 C2H6

Molecular Formula of Ethanoic Acid, CH3COOH

a) Empirical Formula: CH2O

b) Percentage of carbon in ethanoic acid

Finding Empirical Formula

a)

Carbon Hydrogen

Mass (g) 3.6 0.8

No. of Moles (mol) 3.6 ÷ 12 = 0.3 0.8 ÷ 1 = 0.8

Ratio of Moles 3 8

Thus, the empirical formula of the compound is C3H8.

b)

Thus, the molecular formula of the compound is C6H16.




Equation

a)

Cu + 2 Cu + 2

b)No of moles of Cu

= 20g ÷ ( 64+16)gmol-1

= 0.25mol

Ratio of moles Cu : Cu = 1 : 1

So Cu has 0.25mol.

Mass of Cu = 0.25mol

64gmol-1

= 16g

C) S

nthesis (Experiment)

Describe a laborator

experiment to determine the empirical formula of Magnesium oxide.

(*Refer to Chemistry written practical book Activity 3.5)




Chapter 4: Periodic Table of Elements


Periodic Table is arranged according to the increase in proton number.

Group 1

- Atomic size increases

i) When going down the group the number of shells occupied with electrons

increases.

- Density increases

i) The increase in atomic mass is bigger than the increase in atomic radius.

- Melting and boiling point increase

i) The metallic bond between the atoms becomes weaker down the group as the

atomic radius increase. Thus less heat energy is required to overcome the weakerforces of attraction between the atoms during melting/boiling.

- Electro positivity of the metals increases

i) As atomic radius becomes larger down the group the force of attraction between

the nucleus and the single valence electron becomes weaker. ence the elements

lose the single valence electron more easily down the group.

- Reactivity increase

i) Reactivity increases because the atomic size increase the valence electron in the

outermost shell becomes further away from the nucleus. ence attraction between

nucleus and valence electron becomes weaker. Thus the atoms can easily donate

the single valence electron to achieve the stable electron arrangement of the atom

of noble gas.

Group 17

- Reactivity decrease

i) This is because the atomic size of halogen increases. Thus the outermost occupied

shell of each halogen atom becomes further from the nucleus. Thus the strength to

attract one electron into the valence shell by the nucleus becomes weaker.

Group 18

- Melting and boiling point increase

i) Because atomic size of each element increases down the group force of attraction

between the atoms of each element becomes stronger. Thus more heat energy is

required to overcome the stronger forces of attraction during melting/boiling.

- Atomic size increases




i) When going down the group the number of shells occupied with electrons

increases.

- Density increases

i) Because the increases in atomic mass is bigger compared to the increase in volume.

Period 3

- Atomic size decreases from left to right

i) The proton number increases from left to right

ii) The nuclei charge positive charge in the nucleus increases

iii) Nuclei attraction force between the nucleus and the valence electron increase

iv) Valence electron becomes closer to the nucleus

v) Thus the atomic size becomes smaller

Transitional Elements

- The elements from group 3 to group 12 in the periodic table.

- as high melting and boiling point

- as high tensile strength

- Malleable

- Ductile

- as shiny surfaces

- Is a good conductor of heat and electricity

- E

ists as solid state in room temperature

B) Understanding/ Application/ Anal

sis

State position of element

in periodic table

- Element X has an electron arrangement of 2.8.8.2. encej it is positioned at period 4j group

2. (Period= no of shells; Group= valence number)

When across period 3 from sodium to argon, the atomic size decreases. Explain.

- This is because the number of proton increases from left to right. This causes the positive

charge in the nucleus to increase. The nuclei attraction force between the nucleus and the

valence electron increase. The valence shell containing valence electron becomes closer to

the nucleus. k encel the atomic size decreases from sodium to argon.

When across period 3 from sodium to argon, the electronegatim

itn

increases. Explain.

- This is because the number of proton increases from left to right. This causes the positive

charge in the nucleus to increase. The increase of proton causes the valence shell containing

valence electron to be closer to the nucleus. The more the proton numbero the stronger the




force to attract valence electron and electrons into the valence shell. ence the

electronegativity increases across period 3.

Reacti

it

of Group 1 increases down the group. Explain.

- Reactivity increases because the atomic size increase the valence electron in the outermost

shell becomes further away from the nucleus. ence attraction between nucleus and

valence electron becomes weaker. Thus the atoms can easily donate the single valence

electron to achieve the stable electron arrangement of the atom of noble gas

Reacti

it

of Group 17 decreases down the group. Explain.

- This is because the atomic size of halogen increases. Thus the outermost occupied shell of

each halogen atom becomes further from the nucleus. Thus the strength to attract one

electron into the valence shell by the nucleus becomes weaker.

Wh

helium not reactiz

e?

- This is because it is a noble gas which has a stable octet electron arrangement. Thus{ it does

not need to receive or losses any electron making it not reactive.

X is in Group 1. X burnt in oxygen and the product is dissol|

ed in water. What is the property of

solution formed? Explain.

- The solution form is an alkaline solution. It reacts with acid to form salt and water. The

solution formed has this characteristic because group 1 elements are alkali metals whereby

its o}

ide can dissolve in water to form alkali (X ~ ).

Chlorine gas dissol

es in water. What can be obser

ed if a piece of blue litmus paper is immersed

into the solution formed? Explain.

- Chlorine water changes the blue litmus paper into red then white. This happens because

chlorine gas is an acidic gas and when it dissolves in water its acidic properties are

displayed and it becomes hydrochloric acid. The litmus paper then changes into white as

the solution has bleaching properties (

Cl).

- Cl2 + 2 Cl + Cl

W is an element from Group 1. Predict the chemical reaction of W with: water and oxygen (include

obser

ations and chemical equations involved.

Reaction with bservations Equations

Water It reacts quickly with water. The solution

formed changes the red litmus paper into blue.

2W + 2 2 2W + 2

ygen It burns brightly with flame. White solid is

produced and it dissolves in water. The solution

formed changes red litmus paper blue.

4W + 2 2W2

W2 + 2 2W





Describe a laboratory experiment to compare the reactivity of elements in G1: Li, Na, K.


Describe a laboratory experiment to compare the reactivity of elements in G17: Cl, Br, I in thereaction with iron wool.





Chapter 5: Chemical Bond


Anion

- A negatively charged ion

Cation

- A positively charged ion

Ionic Bond

- A chemical bond that involves metal atom and non-metal atom where the metal atom

donates electron to form positive ion (cation) while non-metal atom accepts electron to

form negative ion (anion).

-

ighM

elting and Boiling Pointi) The atoms are held together by strong ionic bond. Thus more energy is needed to

overcome the strong electrostatic forces between the atoms.

- Electrical Conductivity

i) Solid- The ionic compound cannot conduct electricity because the ions in the

compound are constricted in the crystal lattice and unable to move freely.

ii) Molten/Aqueous- The ionic compound can conduct electricity because there are

freely moving ions which carry charges.

Covalent Bond

- A chemical bond that involves only non-metal atoms where electrons are shared to achieve

stable duplet or octet electron arrangements.

- LowMelting and Boiling Point

i) The covalent molecules are held together by weak intermolecular force. Thus less

energy is needed to overcome the bonds between the covalent molecules.

- Electrical Conductivity

i) Covalent compound cannot conduct electricity in any form as the molecules presentin the compound are neutral. There are no ions present and no charge.




B. Understanding/ Application/ Analysis

Why NaCl conduct electricity in aqueous state but cannot conduct electricity in solid state?

- This is because in aqueous state the ions that made up sodium chloride are able to move

freely in the solution. This means that there are charges moving in the solution. ence it can

conduct electricity. owever in solid state the ions are at fi

ed position in a lattice. They

are unable to move around freely. Thus it cannot conduct electricity.

Magnesium chloride and hydrogen chloride are two compounds of chlorine. At room condition,

magnesium chloride exists as a solid but hydrogen chloride exists as a gas. Explain.

Magnesium chloride Aspects of view ydrogen chloride

Solid State at room temperature Gas

Ionic compound Type of compound Covalent compound

igh Boiling point Low

Ionic compound is held

together by a strong bond

called ionic bond. This means

that more heat energy is

needed to break the bonds and

change the state of the

compound. ence at a

moderate room temperature it

is in solid state.

Inference Covalent compound is held

together by weak

intermolecular forces (Van-der-

Waals force). This means that a

small amount of heat energy is

sufficient to change its state.

ence at a moderate room

temperature it is in gas state.

Formation of ionic bond in sodium chloride, NaCl

- A sodium atom has 11 electrons and it has an electron arrangement of 2.8.1. This electron

arrangement is not stable. It needs to donate an electron to achieve an octet electron

arrangement. When a sodium atom donates an electron it will become sodium ion with the

electron arrangement of 2.8.

- Chlorine atom has 17 electrons and it has an electron arrangement of 2.8.7. This

configuration is unstable. It needs to receive one electron to become stable and to achieve

an octet electron arrangement. When a chlorine atom receive and electron it will become

chloride ion with the electron arrangement of 2.8.8.

- When a sodium atom reacts with a chlorine atom

an electron of the sodium atom is given tothe chlorine atom. The positively charged ion Na

+will attract to the negatively charged ion

Cl-to form an ionic compound sodium chloride NaCl. This force enables the two ions to

stick together through ionic bond.

(*Refer to appendi

)




Describe the formation of covalent bond between element from G14 and G17

- E

ample of formation: tetrachloromethane CCl4 (Carbon- G14 ; Chlorine- G17)

- The formula of tetrachloromethane molecule is CCl4. Carbon is in group 14 of the periodic

table. It has four electron in its valence shell. In order to achieve the octet electron

arrangement each carbon atom needs another four more electrons to form an octet

electron arrangement.

- Chlorine atom is in group 17 of the periodic table. It has 7 valence electron. It needs one

more electron to achieve the octet electron arrangement.

- When one carbon atom share one electron with four chlorine atom both carbon atom and

chlorine atom can achieve a stable electron arrangement. This means that each chlorine

atom share a pair of electron with a carbon atom. This indicates single covalent bond.

(*Refer to appendi

)


Draw electron arrangement of the compound formed from the following elements.

a) Nitrogen and ydrogen

b) Carbon and

ygen

c) Magnesium and Chlorine

d) Carbon and ydrogen

e) ydrogen and Chlorine

f) Sodium and o

ygen

(*Refer to appendi

)




Chapter 6: Electrochemistry


Electrolytes

- Substances that can conduct electricity when they are in molten or aqueous solution and

undergoes chemical changes.

Non- Electrolytes

- Substance that cannot conduct electricity either in molten or aqueous solution.

Electrolysis

- A process whereby compounds in molten or aqueous solution are broken down into their

constituent element by passing electricity through them.

Anode

- The electrode that is connected to the positive terminal of a battery

- The negatively charged terminal of a voltaic cell

Cathode

- The electrode that is connected to the negative terminal of a battery

- The positively charged terminal of a voltaic cell

Voltaic Cell

- An electrochemical cell that produces electrical energy from chemical energy

Daniell Cell

- Zinc and Copper as electrodes

Porous Pot/ Salt Bridge

- Avoid the solutions from mi

ing and still allow electrical contact between the two solutions.

Factors affecting electrolysis of an aqueous solution

- Position of ions in the electrochemical series

- Concentration of ions in electrolytes

- Types of electrodes used in the electrolysis

i) Inert( Carbon/ Platinum)

ii) Active (Copper etc.)





Hydrogen chloride in water Aspects Hydrogen chloride inmethylbenzene

Yes Conduct electricity No

This is because in water hydrogen

chloride is in the form of ions as it

has dissociated. The hydrogen ion

and chloride ion present in the

aqueous solution carries positive

and negative charges respectively.

These charges are able to move

freely. ence it is able to conduct

electricity.

Inference This is because in methylbenzene

hydrogen chloride e

ists as neutral

molecules. It has no charge. ence it is

unable to conduct electricity.

Explain the selective discharge of ions at the electrodes.

a) Types of electrodes

b) Concentration of the ions

(*Refer Chemistry written practical book e

periment 6.2 and E

periment 6.3)

Electrolysis of molten lead bromide

1. A crucible is filled with solid lead (II) bromide PbBr2 until it is half full.

2. The apparatus are set up as shown.

3. The solid lead (II) bromide PbBr2 is heated until it is completely molten.

4. The circuit is switched on for about 20 minutes. The changes at the anode and the cathode

are observed.

5. The circuit is switched off and both electrodes are taken out from the electrolyte. The

molten lead (II) bromide is carefully poured into a beaker.

6. What is left at the bottom of the crucible is observed and recorded.

(*Diagram refer to appendi

)

Extraction of Aluminium from Aluminium oxide

1. Cryolite Na3AlF6 is added to aluminium o

ide to lower the melting point to about 850C.

2. The electrodes are made graphite.

3. In the molten state

aluminium o

ide will dissociates to aluminium ions and o

ygen ionsaccording to the following equation:

4. At the cathode:

At the anode:

verall Equation:




5. Oxygen will be formed at the anode. It will burn the graphite electrode to form carbon

dioxide. ence the graphite anode needs to be replaced occasionally.

6. The aluminium is siphoned off as molten aluminium.

(*Diagram refer to appendix)

Daniell Cell

1. The solutions are connected through a salt bridge and porous pot.

Negative terminal Positive terminal

Zinc Copper

Zinc metal becomes thinner because zinc atom

from the electrode loses two electrons to form

zinc ion. Zinc electrode dissolved.

Copper metal becomes thicker because the

copper (II) ions in the copper (II) sulphate

solution receive two electrons to form copper

atoms which are later deposited at the copper

electrode.

Overal ionic equation:

The flow of electrons from the zinc electrode to the copper electrode results in the flow of electrical

current and thus produces electricity.


Dry Cell

Negative terminal Positive terminal

Zinc Carbon

Zinc metal releases electrons and dissolves to

form zinc ions.

Ammonium ions receive electrons to produce

ammonia gas and hydrogen gas.

1. Manganese (IV) oxide MNO2 oxidises the hydrogen gas and minimises the formation of gas

bubbles at the carbon rod when the cell is in use.

2. The flow of electrons from the zinc metal casing (the external circuit) to the carbon rod

results in the flow of electrical current and thus produces electricity.



Extraction of lead from lead (II) oxide

(*Refer to extraction of aluminium)




Anode Cathode

Overall ionic equation:

Selective discharge of ions in electrolysis of cooper (II) sulphate solution

(*Refer to concentration of ion affecting ion discharge)




Chapter 7: Acid and Bases and Chapter 8: Salts


Acid

- Chemical substance which ionizes in water to produce hydrogen ions ª

+

Base

- Chemical substance which ionizes in water to produce hydroxide ions« OH-

Alkalis

- Soluble base

Water

- Help bases to dissociate to produce hydroxide ions¬ OH-

- Without water¬

acid or base cannot exhibits their properties

pH

- The measure of the concentration of H+

andOH-

- The higher the concentration of H+, the lower the pH

- The higher the concentration of OH-, the higher the pH

Strength of Acid

- Depends on the degree of ionization or dissociation of the acid in water

Strong Acid

- Acid which ionizes completely with water to form hydrogen ion, H+(HCl)

Weak Acid

- Acid which partially ionized in water (CH3COOH)

Strong Alkali

- Alkali which ionizes completely with water to form hydroxide ion, OH-(NaOH)

Weak Alkali

- Alkali which partially ionizes in water to form hydroxide ion, OH-(NH3)

Standard Solution

- Solution with an accurate concentration

Neutralisation




- Reaction of an acid and a base.

Monoprotic Acid

- One molecule of acid dissociates or ionizes in water to form one hydrogen ion, H+

Diprotic Acid

- One molecule of acid dissociates or ionizes in water to form two hydrogen ion, H+

Triprotic Acid

- One molecule of acid dissociates or ionizes in water to form three hydrogen ion, H+

Salt

- A compound formed when the hydrogen ion, H+

from an acid is replaced by a metal ion or an

ammonium ion.

Precipitation reaction

- The method used to prepare insoluble salt where two soluble salt solutions are mixed

together.

B) Understanding/ Application/ Analysis

Ammonia in water Aspects Ammonia in trichlomethane

9(alkaline) pH 7 (neutral)

This is because ammonia

partially dissociates in water to

form hydroxide ions. The

presence of hydroxide ions

causes the pH value to

increase.

Inference This is because ammonia exists

as neutral molecules in

trichlomethane. There is no

presence of either hydrogen

ion or hydroxide ion that will

change the pH value. Thus it is

neutral.

80cm3

of distilled water is added to 20cm3

of 2.0moldm-3

solution of HCl. Find molarity of the

diluted solution.

M1V1 =M2V2

2.0moldm-3(20/1000dm3) =M2 (100/1000dm3)

M2 = 0.4moldm-3




Titration, 40cm3

of 0.25moldm-3

potassium hydroxide, KOH solution is needed to neutralise 20cm3

of nitric acid, HNO3. Calculate the molarity of nitric acid.

Why same molarity of different acid needed different volumes in order to neutralise the same

amount of alkali/ base? (Example: Nitric acid and sulphuric acid)

- Sulphuric acid is a diprotic acid, when it dissociates in water to produce two hydrogen ions

per mole.

- Nitric acid is a monoprotic acid, each mole of it dissociates to form one hydrogen ion.

- Thus though same molarity of both acids are used to neutralise the same amount of acid

with the same molarity, higher volume of nitric acid would be used as compared to the

volume of sulphuric acid used because it nitric acid has half the number of hydrogen ion as

compared to sulphuric acid.





Chapter 9: Manufactured Substance in Industry


Alloys

- A mixture of 2 or more elements with a certain fixed composition in which the major

component is metal (elements combined physically)

Aim to produce alloys

- To prevent or minimise corrosion of metal

- To improve physical appearance of metal

- Give the metal a strength boost

Composite materials

- A structural material that is formed by combining two or more different substances such as

metal, alloys, ceramics, glass and polymers

Composite materials Components Used to

Reinforcement Concrete Steel bars and concrete

(cement, sand and small

pebbles)

Construction of large structures like

highways, high-rise buildings,

Bridges, oil platforms and airport runners

Superconductor Yattrium oxide, barium

carbonate, copper(II)

oxide

Used in bullet trains, medical magnetic-

imaging like magnetic resonance imaging

(MRI), magnetic energy-storage,

generators, transformers, computers,

electric cables

FibreOptics Silica, sodium carbonate,

calcium oxide

Transmit data, voice and images in a digital

format

Fibre Glass Glass fibre and polyester

(a type of plastic)

To make household products like water

storage tanks, badminton rackets, small

boats, skis, helmets

Photochromic Glass Glass and silver chloride

or silver bromide

To make optical lenses, car windshields,

smart energy efficient windows in buildings,

information display panels, lens in cameras,

optical switches and light intensity meters

Polymers

- Large molecules made up of many identical repeating sub-unit called monomers which are

joined together by covalent bond

Monomers

Processes Catalyst Temperature Pressure Production

Haber Process Iron 400- 450C 150-300 atp Ammonia

Contact Process Vanadium(v) oxide, V2O5 500C 1-2 atp Sulphuric acid

Ostwald Process Platinum/ Rhodium 850C 5 atp Nitric acid




- A simple compound/ basic unit whose molecules can join together to form polymers

Polymerisation

- A chemical process that combines several monomers to form a polymer or polymeric

compound

Synthetic Polymers, their monomers and uses

Monomer Synthetic Polymer Uses

Ethene Polythene Shopping

Bags, Plastic

bags, and

insulator for

electrical

wiring

Propene Polypropene Piping and

ropes

Chloroethene Polyvinyl chloride, PVC Artificial

leather

Methylmethacrylate Prespex Safety Glass




Benzene-1,4-dicarboxylic acid

Ethane-1,2-diol

Terylene Clothing,

ropes

Hexane-1,6-dioic acid

Hexane-1,6-diamine

Nylon Clothing,

ropes

Type of Glass Components Characteristics Uses

Soda-lime Glass Silicon oxide, sodium

oxide, calcium oxide

Good chemical

durability, high

thermal expansion

coefficient, easy to

make into different

shapes, low melting

point

Bottles, window

panels, mirror, bulbs,

flat glass, glass

containers

Lead Crystal Glass Silicon oxide, sodiumoxide, lead oxide,

potassium oxide,

aluminium oxide

Soft and easy to melt, high density, high

refractive index

Art objects, lens, prisms, chandeliers

Borosilicate Glass Silicon oxide, sodium

oxide, calcium oxide,

Boron oxide,

aluminium oxide

Low thermal expansion

coefficient, resistant to

heat and chemical

attack

Cooking utensils, lab

glassware, automobile

headlights




Fused Glass Silicon oxide High heat resistant,

high transparency,

high melting point,

resistant to chemical

attack

Lab glassware, lenses,

telescope, mirrors

Ceramic

- Made from clay, such as kaolin.

Properties Uses Examples

Strong and hard Building materials Tiles, pipes

Rust proof and chemical

resistance

Kitchen ware Cups, bowls

High melting point Heat insulator Lining of oven and furnace, sealingsurface of space shuttles

Longer lasting and pleasing Decorative items Porcelain, pots, souvenirs

Hard and not compressible Dental and medical uses False teeth and artificial limbs

Electric insulators Electrical items Spark plugs, insulators in toaster and

electric iron


Bronze Copper

Tin atoms are added to the copper atoms

arrangement. Tin atoms are bigger than copper

atoms. As a result, the uniformity of the

arrangement of copper atoms is disrupted and

this prevents the layers of copper atoms to slide

over one another.

This made bronze harder than pure copper.

Copper atoms are arranged in an orderly manner

and are packed close together. Because the

copper atoms are all in the same size, it enables

the layer of copper atoms to slide over easily

when a force is applied.

This shows that pure copper is malleable and

soft.

Acid Rain

1. Release of sulphur dioxide from chimney of factories, and the burning of petrol in cars.

2. The wind carries the pollutant around the globe.

3. Formation of acid rain:

a) Sulphur dioxide in air reacts with water and oxygen to form acid rain.

4. Effects:




a) Acid rain corrodes buildings and metal structures

b) Flows into rivers and lakes causing water pollution

i) Lakes and rivers become acidic

ii) Fish and other organisms die

c) Acid rain destroys trees in forest

d)

Causes soil pollutioni) pH of the soil decreases

ii) salts are leached out of the top soil

iii) roots of trees are destroyed

iv) plants die of malnutrition and diseases

Manufacturing Sulphuric acid

Process named: Contact process

Steps involved:

1. Sulphur is burnt in a furnace together with dry air to produce sulphur dioxide.

2. Sulphur dioxide and air are passed over a converter to be converted to sulphur trioxide with

the presence of:

a) Catalyst: Vanadium (V) oxide, V2O5

b) Temperature: 450-500 C

c) Pressure: 2-3 atp

3. Sulphur trioxide is dissolved in concentrated sulphuric acid to form a product called oleum.

4. Water is added to oleum to produce concentrated sulphuric acid

Manufacturing Ammonia

Process named: Haber process

Steps involved:

1. Nitrogen gas and hydrogen are mixed and scrubbed to get rid of impurities.

2. O

ne volume of nitrogen gas and three volume of hydrogen gas are compressed in thepresence of 150-300 atp.

3. Then, it goes to the converter. The conditions are:

a) Catalyst: Iron

b) Temperature: 400-450C

4. The mixture of gas leaves the converter and is cooled until ammonia condenses. Only 10% of

the mixture will produce ammonia.




5. The rest of the unsuccessful nitrogen and hydrogen gas are then pumpedback to the

converter for another chance to react.

6. The ammonia formed are then liquefied and separated to get a better yield. It is then stored

under pressure tanks.


Preparing Ammonium sulphate

1. Titration (ammonia solution and sulphuric acid)

(*Titration- refer to chemistry written practical book Activity 7.11)

2. Preparation of ammonium sulphate

a) 25.0cm3 of ammonia solution is pipette into a conical flask without adding indicator.

b) From the burette, exactly Vcm3

of sulphuric acid is added to ammonia solution.

c) The reacted solution is poured into an evaporating dish.d) The solution is heated gently until two third of the solution has evaporated (saturated).

The saturated solution is allowed to cool so that the salt crystallises.

e) The solution is filtered to obtain the crystals.

f) The crystals are pressed between sheets of filter paper to dry.

Comparing the hardness of brass and copper

1. A steel ball bearing is stick onto the copper block using a cellophane tape.

2. A 1kg weight is hung at a height of 50cm above the ball bearing as shown in figure.

3. The weight is dropped so that it hits the ball bearing.

4. The diameter of the dent made on the copper block is measured.5. Steps 1 to 4 are repeated twice on the other parts of the copper block in order to obtain an

average value for the diameter of dents formed.

6. Steps 1 to 5 are repeated using a bronze block to replace the copper block.

7. The readings are recorded in a table.





Chapter 10: Rate of Reaction


Rate of Reaction

- The change in quantity of the reactant or products per time unit

- Is a measure of how quickly a chemical reaction happens

Fast Reaction

- The conversion of reactant to products takes place in a short time

Slow Reaction

- The conversion of reactant to products takes more time to complete

Observable Change

- A change that can be observed by our senses

Average Rate of Reaction

- The rate of reaction over an interval of time

Instantaneous rate of reaction

- Rate of reaction at any given time

Catalyst

- A substance that changes the rate of reaction. It does not undergo any chemical change

Decomposition

- A chemical reaction in which a compound is broken down into simpler substances

Effective Collision

- A collision between reactant particles that result in reaction between them

Activation Energy, EA

- The minimum energy the colliding particles must have before collision between them can

result in chemical reaction

Energy Profile Diagram

- A graph that represents the energy change that occurs in a chemical reaction

Collision Frequency

- The number of collisions per unit time




Effective Collision Frequency

- The number of effective collisions per unit time

Collision Theory

- Theory used to explain chemical reactions in terms of collisions between particles, effective

collisions, and activation energy


Factor Change Effect Collision

Frequency

Effective Collision

Frequency

Rate of

Reaction

Size of reactant Smaller Size More total surface area

exposed for collisions

Increase Increase Higher

Larger Size Less total surface area

exposed for collisions

Decrease Decrease Lower

Concentration of

reactant

Increase

concentration

More reactant particles

per unit volume


Decrease

concentration

Less reactant particles

per unit volume


Temperature of

reaction mixture

Higher

temperature

Reactant Particles move

faster


Lower

temperature

Reactant Particles move

slower


External pressure of

a reaction mixture

containing gaseous

reactants

Higher

pressure

More reactant particles

per unit volume


Lower

pressure

Less reactant particles

per unit volume


Catalyst Present Reaction follows pathwith lower Ea - Increase

H

igher

Absent Reaction follows path

with higher Ea

- Decrease Lower




Why hydrochloric acid of 2.0moldm-3

reacts faster with zinc than hydrochloric acid of 0.5moldm-3

?

- This is because 2.0moldm-3

of hydrochloric acid contains a higher concentration of hydrogen

ion and chloride ion per unit volume that is able to react with zinc as compared to

0.5moldm-3 of hydrochloric acid. This means that the reaction between 2.0moldm-3 of

hydrochloric acid and zinc has a higher collision frequency, effective collision frequency and

rate of reaction as compared to the reaction between 0.5moldm-3

of hydrochloric acid and

zinc.


Describe the laboratory experiment to confirm the smaller the size of the reactant, the higher the

rate of reaction by using the reaction between calcium carbonate and hydrochloric acid.

(*Refer to Chemistry Written Practical book Form 5 Lesson 3 Activity sheet)

Describe the laboratory experiment to show that the presence of catalyst will increase the rate of

decomposition of hydrogen peroxide.

1. Test tube A and B are filled with 5cm3

of hydrogen peroxide and are placed in a test tube

rack.

2. Half a spatula of manganese (IV) oxide is put into test tube B.

3. A glowing wooden splinter is inserted into the mouth of both test tubes.

4. The changes on the glowing wooden splinter is observed and recorded.

Describe a laboratory experiment to show that an increase in temperature will increase the rate of

reaction between sodium thiosulphate solution and sulphuric acid.

(*Refer to Chemistry Written Practical book Form 5 Chapter 1 Experiment 3)




Chapter 11: Carbon Compound


Carbon Compound

- A compound that contains carbon, C combined with other elements

Organic Compound

- A carbon compound found in, produced by, or derived from living organisms

Hydrocarbon

- An organic compound that contains only carbon, C and hydrogen, H

Saturated Hydrocarbon

- A hydrocarbon that has only single covalent bonds (Alkane: Butane)

Unsaturated Hydrocarbon

- A hydrocarbon that has double or triple covalent bonds (Alkene: Propene)

Alkane

- A group of saturated hydrocarbons

Structural Formula

- A formula that shows which atoms are bonded to each other in a molecule of the organic

compound

General Formula

- A formula that shows the general form of the molecular formula of a homologous series

Straight-chain Alkane

- An alkane in which the carbon, C atoms are joined in a continuous straight line

Substitution Reaction

- A reaction in which one atom replaces another atom within a molecule

Alkene

- A group of unsaturated hydrocarbons

Addition Reaction

- A reaction in which a molecule adds to the two carbon, C atoms of a double bond

Homologous Series




- A group of organic compounds in which each member differs from the next one in the series

by a fixed unit of structure

Isomers

- Compounds with the same molecular formulae but different structural formulae

Isomerism

- The phenomenon of organic compounds existing as isomers

Alkyl Group

- A side-chain containing only carbon, C and hydrogen, H atoms joined by single bonds

Alcohol

- A homologous series containing the hydroxyl group (-OH)

Functional Group

- An atom or a group of atoms that is responsible for the similar chemical properties of a

homologous series

Hydroxyl Group

- The functional group of alcohols

Hydration

- A reaction in which water is added to a compound

Fermentation

- The reaction in which yeast converts glucose, C6H12O6, into ethanol, C2H5OH

Distillation

- The process of extracting a substance by vaporizing it then condensing the vapour

Carboxylic Acid

- A homologous series containing the carboxyl group (-COOH)

Carboxyl Group

- The functional group of carboxylic acids

Esterification

- The reaction between a carboxylic acid and an alcohol to form an ester and water. The

reaction is catalyzed by hydrogen ion, H+




Ester

- A homologous series containing the carboxylate functional group

Extraction of Ester

- To take out the ester from its natural sources (fragrant plants)

Oils and Fats

- Natural Esters

Fatty Acid

- A carboxylic acid that has a long chain of about 10 to 20 carbon , C atoms. It has only one

carboxyl group

1,2,3-propanetriol/ glycerol

- An alcohol that has three hydroxyl groups

Saturated Fat

- Has a higher proportion of saturated fat molecules than unsaturated fat molecules

Unsaturated Fat

- Has a higher proportion of unsaturated fat molecules than saturated fat molecules

Hydrogenation

- The addition of hydrogen, H2 to the double bond between two carbon, C atoms

Natural Rubber

- Polymer obtained from the latex of the rubber tree

Elasticity

- The ability to return to the original shape after being stretched, compressed, or bent

Latex

- A milk- like colloid obtained from the rubber tree

Coagulation of Latex

- The separation of rubber particles from the water in the latex

Polymer: Refer to Form 4 Chapter 9: Manufactured Substances in Industry




Chapter 12: Oxidation and Reduction


Redox Reaction

- A reaction in which oxidation and reduction occur at the same time

Oxidation Number/ Oxidation State

- The imaginary charge of an atom if it exists as an ion

Oxidation

- A chemical reaction in which a substance gains oxygen, O; loses hydrogen, H; loses

electrons; or undergoes an increase in oxidation number

Reduction

- A chemical reaction in which a substance loses oxygen, O; gains hydrogen, H; gainselectrons; or undergoes a decrease in oxidation number

Oxidizing Agent

- Oxidizes a substance. It is reduced in the redox reaction

Reducing Agent

- Reduces a substance. It is oxidized in the redox reaction

Oxidizing agent Reducing agent

Acidified potassium manganate(VII) solution ,

KMNO4

Chloride ion, Cl-

Acidified potassium dichromate(VI) solution,

K2Cr2O7

Bromide ion, Br-

Chlorine water, Cl2(aq) Iodide ion, I-

Bromine water, Br2(aq) Sulphate (IV) ion, SO42-

Iron (III) ion, Fe3+

Sulphur dioxide, SO2 gas

Hydrogen sulphide, H2S

Corrosion of a Metal

- The oxidation of the metal through the action of water, air, and/or electrolytes

Rusting of Iron, Fe

- The corrosion of iron, Fe. It is a redox reaction in which iron, Fe is oxidized to form hydrated

iron (III) oxide, Fe2O3.3H2O or rust

Reactivity Series of Metals

- An arrangement of metals in the order of their reactivity towards oxygen, O2




Vigour of a Chemical Reaction

- Shows how reactive the reaction is

The Extraction of Metal

- The process of obtaining a metal from its ore

Electrolytic Cell

- An electrochemical cell that uses electricity to produce a chemical change

Chemical/ Voltaic Cell

- An electrochemical cell that produces electricity from a chemical change






Chapter 13: Thermochemistry


Exothermic Reaction

- A chemical reaction that releases energy (in the form of heat) to the surroundings

Endothermic Reaction

- A chemical reaction that absorbs energy (in the form of heat) to the surroundings

Energy Level Diagram

- A graph that shows the energy change of a chemical reaction

Heat of Reaction, H

- The energy change of a chemical reaction. It is the difference between the energy of the

reactants and the energy of the products

Thermochemical Equation

- A chemical equation with the heat of reaction, Hwritten at the end of the equation

Heat of Precipitation

- The energy change when one mole of precipitate is formed from its ions

Heat of Displacement

- The energy change when one mole of metal is displaced from its salt solution by a more

electropositive metal

Heat of Neutralization

- The energy change when one mole of water is formed from the neutralization between one

mole of hydrogen ions, H+

from an acid and one mole of hydroxide ions, OH-from an alkali

Heat of Combustion

- The heat given off when one mole of substance is burnt completely in excess oxygen, O2

Fuel Value/ Heat Value

- The amount of energy (measured in kilojoules) that can be obtained when 1g of fuel is burnt




Chapter 14: Chemical for Consumers


Soap

- The salt formed when a fatty acid is neutralized by an alkali

Detergent

- The salt formed when an alkyl hydrogen sulphate is neutralized by an alkali

Additives

- Substances added to a detergent to increase its effectiveness

Biological Enzyme

- An organic catalyst

Whitening Agent

- An additive that makes clothes whiter and cleaner

Saponification

- The hydrolysis of an ester. The catalyst is an alkali

Hydrolysis

- A reaction of a compound with water

Surface Tension

- The attractive force between water molecules. This force prevents water from wetting the

surface

Food Additive

- Any substance that is added to food to preserve it or improve its flavour and appearance

Preservative

- Food additives that prevent or slow down spoilage of food

Antioxidant

- Food Additives that prevent oxidation of food

Flavouring Agent

- Food additives that give flavour to food or enhance its natural flavour




Stabilizers and Thickening Agents

- Food additives that improve the texture and consistency of food

Dyes

- Food additives that colour food or replace lost colours

Drug

- Any natural or artificial made chemical that is reused as a medicine

Traditional Medicines

- Medicines that are derived from plants and animals

Modern Medicines

- Medicines that are manufactured on a large-scale for consumers

Analgesic

- Modern medicines that relieve pain

Antibiotics

- Modern medicines that kill bacteria

Psychotherapeutic Medicine

- Modern medicines used to treat mental illness

Side Effects of a Drug

- The undesirable effects that the drug produces in addition to that intended

Checklist Chemistry 2009 Yvonne

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