CHEMISTRY FORM 3 SYLLABUS - Webs

Chemistry – Form 3 Page 3 o Assessment marks will be given according to file maintenance and presentation. 2 Copybooks (120 pages) for HW, CW and writ...

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Chemistry – Form 3

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CHEMISTRY FORM 3 SYLLABUS These are the topics we shall be covering together during this scholastic year 2004/5 which is based on the SEC syllabus and suggested Junior Lyceum Syllabus for Form 3. The texts we shall be using are: GSCE Chemistry Chemistry for You o Material from A New Certificate Chemistry 6th edition will also be available. o o

UNIT 1 BASIC CHEMISTRY Topic

1.1 1.2 1.3 1.4 1.5 1.6 1.7

States of matter. Change of state. Physical and chemical change. Elements. Metals and non-metals. Elements and compounds. Compounds and mixtures. Mixed states. Separation techniques.

UNIT 2 NATURE OF MATTER ATOMIC STRUCTURE CHEMICAL BONDING Topic

2.1 2.2 2.3 2.4 2.5

Nature of matter. The kinetic particle theory. Structure of the atom. Isotopy. Electrovalent bonding. Covalent bonding. Chemical nomenclature. Chemical formulae.

UNIT 3 THE ATMOSPHERE . COMBUSTION. RESPIRATION. RUSTING AND PHOTOSYNTHESIS. OXYGEN AND ITS COMPOUNDS. OZONE Topic

3.1 3.2 3.3 3.4 3.5

UNIT 4 WATER

The composition of air. Air pollution. Combustion. Comparison of combustion and respiration. Rusting. Photosynthesis. Oxygen and its compounds. Ozone.

Chemistry – Form 3

Topic

4.1

4.2

4.3 4.4 4.5

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Occurence. Physical properties. Impurities in water and their removal. Water pollution. Solvent action of water. Solution and solubility. Water of crystallisation; Efflorescence, deliquescence and hygroscopy. Synthesis of water. Tests for water. Chemical properties of water. Hardness of water.

UNIT 5 ACIDS, BASES AND SALTS. Topic

5.1

5.2 5.3 5.4 5.5

Acids. Investigation of the properties of acids. Chemical equations. Bases and alkalis. Investigation of the properties of alkalis. Neutralisation. Salts and acid salts. Preparation of salts. Hydrogen and its compounds.

UNIT 6 THE MOLE CONCEPT. Topic

6.1

6.2

6.3 6.4 6.5

Relative atomic mass. The mole of atoms. Molar mass and Avogadro's constant. Relative molecular mass and relative formula mass. Mole of molecules. Mole of ions. Practical applications of the mole concept. Gravimetric Analysis. Percentage composition by mass. Mass relationships in chemical reactions.

Materials required:

 WELL-KEPT file for keeping handouts in an organised manner.

Chemistry – Form 3

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o Assessment marks will be given according to file maintenance and presentation.  2 Copybooks (120 pages) for HW, CW and written notes o orange cover.  Science Book (alternate line and blank white pages) o This will be for the experimental work

Some things to keep in mind: 1

This course will be leading you to the O-level (SEC) exam.

2

This is NOT a COMPULSORY subject but one that has been freely chosen… so it is important that you take it seriously or else it may be better if you consider another option.

3

It is essential that work (both HW and practical) be handed in on time in order to be able to enter for and to follow the next lessons.

4

A part of this course consists of practical work. The experiments you will do and report on during these 3 years have 15% of your O-level (SEC) global mark, so they should be carried out carefully.

5

Not everything may be clear at a first glance so feel free to ask if things are not understood well.

6

Be careful and follow the laboratory safety rules even when not carrying out experimental work.

7

Respect your classmates and act Responsibly.

Hope you’ll find Chemistry an enjoyable learning Experience! Ms. Rita Buttigieg

Writing a Lab Report Tips on How to Report an Experiment

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1.

First of all it is important to write the DATE on which the experiment was carried out.

2.

The next step is to write the TITLE of the experiment The pH of apple juice

3.

In the AIM you state why you are doing this experiment; what do you want to find out. To determine whether apple juice is acidic, alkaline or neutral or To determine the pH of apple juice

4.

MATERIALS REQUIRED: - In this section you make a list of all the apparatus, chemicals and anything else that may have been used during the experiment.

5.

DIAGRAM:

-

This should be  On the blank page of the science book  In pencil  Clearly labelled; also in pencil  It should also have a caption (a short description beneath it).

6.

METHOD:

-

Make a numbered list of how the experiment was carried out, step by step, as clearly as possible. This should be in the passive tense.

The beaker WAS PLACED on the Bunsen burner NOT

I PLACED the beaker on the Bunsen burner

7.

PRECAUTIONS: - These are things you have to be careful for during the experiment, including safety procedures you may need to take and the reasons for them. List them one by one. e.g.

8.

Gloves were worn when handling the hydrochloric acid.

RESULTS:

-

In this part you state clearly what you observed after carrying out all the necessary steps in the experiment. Sometimes a graph should be plotted from the values obtained.

The indicator turned purple after we added it to the apple juice.

Chemistry – Form 3

9.

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DISCUSSION : Explain a little bit the theory behind this experiment and whether your results agreed with this theory. e.g. you say what is pH and how it is determined, if you expected the apple juice to be acid or alkaline and if the results agree with what you expected.

10.

CONCLUSION: In this section you say in 2 or 3 sentences whether the AIM of the experiment was reached or not and what you learnt and discovered from this experiment.

So as you see, we can practically divide a report in these 10 parts each of which is extremely important and should therefore be included. How will the Reports be marked? Each report will have a total of 15 marks, which will generally be distributed as follows:

(a) Date, Title & Clearly stated Aim (b) Materials needed (c) Well-labelled and presented diagram (d) Method (e) Precautions (f) Results (g) Discussion (h) Conclusion

– 1 mark – 1 mark – 2 marks – 2 marks – 2 marks – 2 marks - 3 marks - 2 marks

Marks will be decreased if: The report is handed in late The report is not well-presented

You may find it useful to take some rough notes during the experiment explanation that can then be used when writing down your report.

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1.1

States of matter

Chemistry for You – Chapter 1 pgs 6-7, 10-11 GCSE Chemistry Chapter 1 – pgs 1-5

See

Complete the following: A)

List 3 physical differences between solids, liquids and gases in the columns below: SOLIDS

B)

LIQUIDS

GASES

Find the melting and boiling points of the following elements (C4U pg. 390): Element

Melting Point

Boiling Point

Iron Krypton Copper Bromine Silicon

Element

Melting Point

Boiling Point

Mercury Xenon Oxygen Nickel Argon

Which of the above would be solid/s at room temperature? _________________________ Which of the above would be liquid/s at room temperature? _________________________ Which of the above would be gas/es at room temperature? _________________________

HW on this unit part: -

(on the copybook)

Chemistry for You –

Pg. 13 no. 1-3, 6; Pg. 37 no. 1-3

GCSE Chemistry -

Pg. 3 no. 1; Pg. 5 no. 4, 5;

2 (optional)* 1-3 (optional)

*Note: Optional Material is for who wants to go into more in detail on the topic, the material is not directly covered by the syllabus – so feel free to do or not to do it.

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States of matter 2 SOLIDS, LIQUIDS & GASES These are the 3 states of matter. Normally a substance can exist in all 3 states. e.g. the compound water can be in the solid state as ice; in the liquid state as water; in the gas state as steam • • • •

Melting – Solid changes into liquid; Freezing – Liquid changes into solid; Boiling/evaporating – liquid changes into gas. Condensation is when a gas changes into a liquid.

A substance melts/freezes at the melting point A substance boils/condenses at the boiling point A liquid begins to boil when bubbles of gas are formed inside the liquid. When a substance is changing state the temperature does not change. The heat energy is being used to change the state of the substance. So when ice is melting the temperature remains 0oC until all the ice has melted. Likewise boiling water will keep a temperature of 100oC until it has boiled away.

Pure substances have sharp melting points and boiling points. Impure substances do not have sharp melting points and boiling points. When impure, the freezing point becomes lower. So impure ice melts at a temperature below 0oC. When impure the boiling point becomes higher. So impure water boils at a temperature higher than 100oC. You can determine if a substance is a solid, liquid or gas at room temperature (27oC) by looking at its boiling and melting points. E.g. Platinum M.P. 1772 oC B.P. 3720 oC At 1772 oC it becomes a liquid (melting point) At 3720 oC it becomes a gas (boiling point) So at 27 oC it is still a solid (lower than M.P) E.g. Neon

M.P. -249 oC B.P. -246 oC

At -249 oC it becomes a liquid (melting point) At -246 oC it becomes a gas (boiling point) So at 27 oC it is already a gas (higher than M.P.

Chemistry – Form 3

1.2 See

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Physical & Chemical change Chemistry for You – Chapter 2 pgs 22-23

It is a fact that changes can occur in matter. However, not all the changes are the same and they are grouped into 2 categories: - physical and chemical changes. The table below mentions some qualities that allow us to distinguish between these types of changes. Table 1 : Physical and Chemical changes (adapted from NCC pg. 5) Physical Change

Chemical Change

1. Produces no new kind of matter

1. Always produces a new kind of matter

2. Is generally reversible

2. Is generally not reversible

3.

3. Is usually accompanied by a

Is not accompanied by a great heat change

considerable heat change

4. Produces no change of mass

4. There is a change of mass between the individual substances produced and the original ones. e.g. A + B = C + D mass of C is different from A or B; & mass of D is different from A or B

Group the following changes into Physical or Chemical Changes. Magnetisation of Iron

The rusting of Iron

The burning of any substance is air

Explosion of natural gas

The heating of a metal wire by electricity

Vaporising a liquid to a gas Physical Change

HW on this unit part: -

(on the copybook)

Chemistry for You –

Pg. 27 no. 1c, 2 Pg. 39 no. 17

Melting a solid to a liquid

Burning Wood Chemical Change

Is this change physical???

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1.3 Elements See

Chemistry for You – Chapter 2 pgs 14 - 16 GCSE Chemistry Chapter 2 – pgs 13 - 16 1

Elements are substances that contain only 1 type of ATOM.

E.g. The element iron contains only Iron atoms 2

Every element has a symbol that is used by people all across the world.

E.g. The symbol of the element Iron is Fe. 3

Elements can be in the solid, liquid or gas state.

4

There are 92 natural elements that occur in nature.

5

Some other elements have been created in the laboratory.

6

We arrange the elements in the periodic table.

7

Dmitri Mendeleev was a scientist that worked a lot on the periodic table. (C4U pg.393)

An element is a substance, which cannot, by any known chemical process, be split up into 2 or more, smaller substances!!! o All the things on the planet earth are made of these elements including human beings. o The number of chemical substances known is approximately 4, 000, 000 (4 million). o All of these (except the elements themselves) are made up of 2 or more elements joined together. These are called compounds.



On your CW make a list of 10 elements and their symbols.

HW on this unit part: -

(on the copybook)

a. Name 5 elements that have been created in the laboratory b. Chemistry for You – c. GCSE Chemistry -

Pg. 27 no. 1a; Pg. 38 no. 6 Pg. 16 no. 1-2

Chemistry – Form 3

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Chemistry for You – Chapter 2 pgs 14 -17 GCSE Chemistry Chapter 2 – pgs 16-17

See

1.3

(cont)

Metals and Non-Metals

Both metals and non-metals are elements. There are more metals than non-metals. The following are the main differences between them: Metals High Melting-points and boiling points Shiny Give a ringing sound when struck Conduct electricity Hard and strong

Non-Metals Low Melting points and boiling points Dull Brittle Insulators (do not conduct electricity) Not so hard and strong.

 On your copybook o

Write the names of 5 metals and 5 non-metals.

o Make a table comparing the properties of metals and non-metals (see pg. 15 GCSE chem.)

1.4 Elements & Compounds An element is a substance made up of only 1 type of atom. For example Aluminium is an element because is made up of only Aluminium atoms. Sodium is an element because it is made up of only Sodium atoms.

There are more than 115 different atoms and so more than 115 different elements. A compound is a substance containing 2 or more elements bound together. For example water is a compound because it contains oxygen and hydrogen atoms bound together. Iron sulphide is a compound because it contains iron and sulphur (2 elements) bound together.

HW on this unit part: - (on the copybook) Chemistry for You –

Pg. 27 no. 1b, 3 Pg. 38 no. 6-8

Chemistry – Form 3

1.5 GCSE Chem pg. 19

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Compounds and Mixtures A mixture consists of 2 or more substances mixed together. In a compound, 2 or more elements are chemically bound together.



Some iron filings and sulphur powder are mixed together. A mixture of iron and sulphur is formed.



The 28g of iron filings and 16g of sulphur are mixed together, then heated in a test tube. When a glow appears, the heating is stopped. The contents in the test tube continue to glow and a black solid is formed.

Differences between Compound and Mixtures: Compound

Mixture

1) The elements making up the compound cannot be separated by physical means. e.g. the iron sulphide cannot be separated (split up) by evaporation, etc. A magnet does not bring about the separation and sulphur; Nothing happens when the compound is shaken with water.

The substances making up the mixture can be separated by physical means. E.g. if a magnet is used, the iron filings are attracted to it. Sulphur remains at the bottom. If water is added to the mixture and the test-tube shaken well, the iron and sulphur will settle as separate layers.

2) A compound has a set of properties, which are totally different from the constituent elements. e.g. if hydrochloric acid is added, and warmed gently, a gas with a disgusting smell is given out. It is hydrogen sulphide and burns with a blue flame.

The properties of the mixture are the sum properties of the substances making up the mixture. e.g. If hydrochloric acid is added to the mixture, hydrogen gas is given out. It explodes with a pop. The iron has retained the property of reacting with acids and displacing hydrogen. The sulphur does not react.

3) A particular compound always contains the same elements in the same proportions. e.g. Fe : S = 28 : 16

A mixture varies widely in its composition. e.g. a mixture of iron and sulphur may have any mass ratio.

4) When a compound is formed (so there is a chemical change = a chemical reaction), there are external effects like heat, light, sound or change in volume. E.g. when the iron sulphide was formed, a red glow appeared which persisted even after heating was stopped.

Mixing is not accompanied by any external effects. E.g. when mixing iron and sulphur, nothing happens, no heat is liberated, etc.

Light & Heat indicate a new compound is formed

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1.6/1.7 Mixed States & Separation see GSCE Chemistry pgs. 20-22 A.

Solid/Liquid Mixtures

Examples include:  salt and water  sand and water  chalk and water 1. Filtration – If we have a mixture of sand and water, these can be separated by filtering. The sand is insoluble, so it remains on the filter paper as residue while the water passes as the filtrate. Both SOLID and LIQUID can be collected.

2. Evaporation – If the solid is soluble filtration is not useful as nothing will remain on the filter paper. So the solution is heated in an evaporating dish (as shown below) and while the solvent (e.g. water) evaporates the solute (e.g. salt) is left behind. The solid is collected.

3. Crystallization – This is a process similar to the one above. The solution is evaporated so it becomes more concentrated. To check if it is concentrated enough a drop of it can be put on a slide, and if crystals form, the solution is left to cool and crystallize. The crystals can then be removed by filtering, washed and dried. Only the solid is collected.

4. Distillation: - to obtain a solvent from a solution. The round-bottomed flask contains the solution, and the liquid (distillate) is collected in the other flask. The Liebig condenser condenses the vapour into liquid, which is collected in the flask. Cold water is continuously passed from the

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condenser against the flow of the gas so it condenses on the cold surface created. The distillate is collected and the temperature is noted.

B.

Liquid/Liquid Mixtures

5)

Immiscible liquids:

Using a Separating Funnel (Tap funnel)

A mixture of oil and water can be separated in this way. The oil floats on top. The tap is opened until all the water has run out. Then it is closed and another beaker put in place to collect the oil.

6)

Miscible liquids: Using Fractional Distillation

If the mixture contains liquids whose boiling temperature varies only by a few degrees, a fractionating column has to be used and the process is called fractional distillation. E.g. To separate ethanol (78oC) and water (100oC). Its important to know well the following steps: a)

When the mixture is heated, and the temperature reaches 78oC, ethanol begins to boil and

some water vapour evaporates too. The vapour condenses on the glass beads making them hot. b)

When the glass beads have a temperature of 78oC, the ethanol vapour passes without

condensing, while the water vapour continues to condense and drips back in the flask. c)

The ethanol vapour passes in the condenser where it condenses and is collected in the flask.

d)

When the temperature rises about 78oC, it means all the ethanol evaporated so heating is

stopped.

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C.

Solid/Solid Mixtures

7)

Separating a mixture of salt and sand. (Refer to Experiment 2 carried out in the Lab)

This is an example of a soluble/insoluble mixture (salt is soluble in water, sand is insoluble). Water is added to the mixture. The contents are stirred till all the salt dissolves and the water is heated till it boils. While still hot the mixture is filtered. The sand remains in the filter paper, and is washed and dried. The salt water (filtrate) is transferred to an evaporating basin and then heated on a steam bath, until all the water has evaporated. Salt remains in the basin. 8)

Separating a mixture of salt and iodine.

This is an example of a volatile/non-volatile mixture. The mixture is heated in a test tube. Iodine sublimes (changes from solid to gas when heated, skipping the liquid stage) and its vapour (gas) solidifies on the upper cooler part of the test tube. The heating is continued till the substance at the bottom of the test tube becomes colourless. The iodine can be scraped from the top part.

9)

Separating Colours -CHROMATOGRAPHY - ink is a mixture of coloured substances Various methods are possible

A) A filter paper is placed on top of a beaker. A small drop of ink is placed in the center of the filter paper. When it has dried more drops are placed (not making the spot too large). A suitable solvent like acetone is dripped in the ink spot, 1 drop at a time (allowing previous ones to dry) and the ink separates into rings of colour. The separation depends on: -

 the solubility of colour in the solvent  how much the colour is adsorbed (clings) to the filter paper (the less it clings the more it moves) B) The ink spot is placed in the center of the filter paper. A wick is cut and is placed in the solvent. The solvent rises up the wick and then spreads outwards from the center. When the solvent almost reaches the edge of the filter paper, the wick is removed from the solvent and the filter paper allowed to dry. c) In another method a rectangular filter paper is used. A base line is drawn by pencil near the end (above the level of the solvent) and the colour is dotted on it. The filter paper is then stood in the jar with a lid (that reduces solvent evaporation). The solvent rises up carrying the colours. When the solvent almost reaches the top, the filter paper is removed and left to dry.