Page 4 - 1202 Question Bank Chemistry Form 4 KSSM

MUST

KNOW Important Facts

Matter and the Atomic Structure Acid, Base and Salt
Electron • Only the sulphate salts below decompose when heated.
Symbol: e – Proton FeSO → Fe O + SO + SO
3
2
4
Relative charge: –1 Symbol: p ZnSO → ZnO + SO 2 3
4
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1 Relative charge: +1 CuSO → CuO + SO 3
Relative mass: 4 3
1 840 Relative mass: 1 (NH ) SO → 2NH + H SO
4
2
3
4 2 4 Ammonia gas Sulphuric acid vapour
• All chloride salts ARE NOT decomposed by heat, except
ammonium chloride.
NH Cl → NH + HCl
4
3
Ammonia Hydrogen
gas chloride gas
Neutron • Most metal carbonates decompose to form metal oxides and
Symbol: n carbon dioxide gas when heated.
Relative charge: 0 (neutral) • However, potassium carbonate and sodium carbonate ARE
Relative mass: 1 NOT decomposed by heat.
Important Facts (Chapter 2) 13 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 6) 19 @ Pan Asia Publications Sdn. Bhd.
The Mole Concept, Chemical Formula and Equation Rate of Reaction
• Diagram shows the relationship between number of moles, • Collision Theory.
mass of substance, number of particles and volume of gas. • Factors affecting the rate of reaction
× Molar mass ÷ N ❖ Size of reactant
A ❖ Concentration
❖ Temperature
Number of Number of particles: ❖ Catalyst
Mass
moles, n atom, molecules, ions
• When frequency of collision between particles increases,
frequency of effective collision between particles increases.
÷ Molar mass ÷ N A This causes the rate of reaction to increase.

÷ Molar volume × Molar volume

Volume of gas

Important Facts (Chapter 3) 15 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 7) 21 @ Pan Asia Publications Sdn. Bhd.

Chemical Bond Manufactured Substances in Industry

• Metallic bond Type of alloy Composition
Duralumin • Aluminium, 93%, • Magnesium, 3%
• Copper, 3% • Manganese, 1%
Bronze • Copper, 90% • Tin, 10%
+ + + + + + + + + + Positively
electron + + + + + + + + + + charged Brass • Copper, 70% • Zinc, 30%
metal ion
+ + + + + + + + + +
+ + + + + + + + + + Steel • Iron, 99% • Carbon, 1%
+ + + + + + + + + +
Delocalised electrons Stainless steel • Iron,73% • Chromium, 18%
from “sea of electrons”
• Nickel, 8% • Carbon, 1%
Pewter • Tin, 95% • Antimony, 3.5%
• Copper, 1.5%
Important Facts (Chapter 5) 17 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 8) 23 @ Pan Asia Publications Sdn. Bhd.