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1. Empirical formula

the simplest whole number ration of atoms of each element in the compound. Molecular formula the actual number of atoms of each element that are present in a molecule of the compound Make sure you know how to calculate the empirical formula & molecular formula.

Element C H

Mass (g) 16.8 2.1

Number of moles

= 1.4

= 2.1

Ratio

= 1

= 1.5

Simplest ration 1 x 2 = 2 1.5 x 2 = 3

EF is C2H3 If given molar mass / relative molecular mass of the compound is 54. MF = (EF)n 54 = (C2H3)n 54 = [(2x12)+3]n n = 2 so, MF is C4H6. Must know why EF of PbO / CuO / SnO cant determine by using the crucible method.

Must know how to write equation and do the calculation.

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2. Periodic Table Must know why when across the period, the electronegativity increases

o Size of the elements decreases when across the period from left to right, o The strength of the nucleus to pull electrons increases (+ve charges increases)

Must know why G18 inert

o Because already achieve stable octet / duplet electron arrangement which does not need to receive, donate or share electrons.

Must know the 4 special properties of transition elements o Form color compound (give example) o Have different oxidation number (give example) o For complex ion (give example) o Use as catalyst (give example)

Reactivity of G17

o the reactivity decreases down the group o size increases when going down the group, the forces of attraction between the

nucleus and the electrons become weaker o Must know the reactivity of G17 reacts with iron

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3. Acid & bases Must know how to use the dilution formula for calculation

Must know how to write the correct neutralization equation

Must know the color change for the indicator use

Must know the calculation involving the neutralization

Must know the definition of strong / weak acids / alkali 4. Salts

Must know how to prepare soluble salt o If soluble salt type of Na / K / NH4 , use neutralization o If soluble salt not the type of Na / K / NH4 , use acid + metal oxide / metal carbonate

Must know the cation Test

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Must know the Anion Test

5. Electrolysis Take note for the concentration factor.

o Please remember that, if the electrolyte contains Chlorine / Bromine / Iodine, the electrolyte is consider concentrated if the concentration is 0.1 M and above

o Make sure know how to write the half equation for anode and cathode

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Voltaic cell

o Constructing the ECS o Half equation o Observation

Different between electrolytic cell and voltaic cell

6. Contact process

The catalyst use, temperature

Must know why SO2 is not dissolve in water to produce H2SO4

Pollution cause by SO2 7. Rate of reaction

Make sure know how to describe experiment (Sodium thiosulphate) o Temperature o Total surface area

Must know how to explain the rate of reaction in term of collision theory

Must know how to draw a tangen to find the gradient

8. Carbon Compounds

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Must know how to draw the isomer

Homologous Series o Members of the series can be represented by a general formula o Successive members differ from each other by –CH2 o Physical properties change regularly with increasing number of C atoms per

molecule o Members have similar chemical properties because they have the same functional

group o Members can be prepared by similar methods

9. Redox reaction

Must know how to explain redox reaction in term of transferring of electron and change of oxidation number

Rusting of iron

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How to prevent rusting

Investigating rusting of iron

Redox reaction (transferring of electron at a distance)

10. Heat of reaction

Must know how to do the calculation to find H o 2 type of question :

In an experiment, 25 cm3 of silver nitrate 0.2 mol dm-1 was reacted with 0.7 g copper powder. The copper powder used was more than what is required. The reaction produced a rise in temperature of 3.5°C. (a) Write down the equation for the reaction. (b) Calculate:

i. the number of moles of silver ions in the solution. ii. the total heat energy liberated. iii. the heat of displacement.

ANSWER (a) Cu(s) + 2Ag+(aq) Cu2+(aq) + 2Ag(s)

(b) i. Number of moles of Ag+ = 𝑀𝑉

000 =

0 × 5

000 = 0.005 mol

ii. Heat energy, E = mc = 25 x 4.2 x 3.5 = 367.5 J

iii. H = 𝐸

𝑚𝑜𝑙𝑒 =

3 7 5

0 005 = –73.5 kJ mol-1.

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Must know the definition for all the 4 heat of reaction

Must know how to draw the correct energy level diagram

Precautionary steps 11. Chemical for consumer

Soap & detergent o Cleansing action o Saponification equation o Effectiveness of the cleansing action (hard water, acidic water)

Food additives

o Must know all type of food additives (preservatives, flavouring agents, coloring, thickening agent, antioxidants, stabilisers)

Medicine o Must know the function, example and side effect for Analgesic, antibiotic and

psychotherapeutic