ID CSC Chemistry Lecture Notes

Introduction

• Lecture covers 91 new specification for Excel all-in-one chemistry.
• Mention of answer revision guides available on www.hyken.com.

States of Matter: Solids, Liquids, Gases

• Solids: Particles in fixed arrangements, vibrate in fixed positions, little kinetic energy, strong forces.
• Liquids: Particles more widely spaced, intermediate forces, particles vibrate more.
• Gases: Particles further apart, large kinetic energy, weak forces.

Conversions Between States

• Solid to Liquid: Melting.
• Liquid to Solid: Freezing.
• Liquid to Gas: Boiling/Evaporating.
• Gas to Liquid: Condensation.

Evaporation

• Particles with most energy evaporate first, lowering average kinetic energy.
• Condensation and evaporation occur simultaneously in closed containers.

Diffusion

• Definition: Movement of particles from high to low concentration, passive process.
• Example: Ammonia and hydrochloric acid diffusion producing ammonium chloride.

Solutions and Mixtures

Key Terms

• Solute: Solid that dissolves in a solvent (e.g., coffee grounds).
• Solvent: Liquid in which solute dissolves (e.g., hot water).
• Solution: Mixture of solute and solvent (e.g., coffee).
• Saturated solution: Cannot dissolve more solute.

Types of Substance

• Atom: Smallest particle of a substance.
• Element: One type of atom, cannot be split chemically.
• Compound: Two or more elements chemically combined.
• Mixture: Two or more elements not chemically combined.

Separation Techniques

Methods

• Filtration: Separates insoluble solute from solvent (e.g., sand and water).
• Evaporation: Separates soluble solute from solvent (e.g., salt and water).
• Distillation: Separates liquids with different boiling points (e.g., ethanol and water).
• Chromatography: Separates liquids by solubility (e.g., dyes).

Atomic Structure

• Atom: Nucleus with protons and neutrons, electrons in shells.
• Protons/Neutrons: Mass of 1, electrons have smaller mass.
• Charge: Neutrons are neutral, protons are +1, electrons are -1.
• Atomic/Mass Number: Atomic number equals proton number, mass number is protons + neutrons.

Periodic Table

• Groups: Columns, number of electrons in outer shell.
• Periods: Rows, number of electron shells.
• Metals vs. Nonmetals: Metals on left, nonmetals on right of step line.

Ionic and Covalent Bonding

Ionic Bonding

• Between metals and nonmetals, transfer of electrons.
• Examples: Magnesium oxide, magnesium chloride.

Covalent Bonding

• Between nonmetals, sharing electrons.
• Examples: Water (H2O), methane (CH4), carbon dioxide (CO2).

Chemical Structures

Giant Structures

• Ionic: High melting points, conductive when molten.
• Covalent: Diamond and graphite (allotropes of carbon).
• Metallic: Sea of electrons, conductive.

Group 1 and Group 7 Elements

Group 1: Alkali Metals

• Reactive, low melting/boiling points, stored in oil.
• React with oxygen, water, halogens.

Group 7: Halogens

• States at room temperature: Fluorine (yellow gas), Chlorine (green gas), Bromine (red-brown liquid), Iodine (grey solid).
• Reactivity decreases down the group.

Environmental Chemistry

Carbon Dioxide and Acid Rain

• CO2: Greenhouse gas, causes global warming.
• Acid Rain: Formed from sulfur and nitrogen oxides, harms environment.

Organic Chemistry

Alkanes and Alkenes

• Alkane Formula: CnH2n+2, saturated.
• Alkene Formula: CnH2n, unsaturated, contain double bonds.

Fractional Distillation

• Separates crude oil into fractions based on boiling points.
• Fractions: Refinery gases, petrol, kerosene, diesel, fuel oil, bitumen.

Combustion

Complete vs. Incomplete

• Complete: Plentiful oxygen, produces CO2 and water.
• Incomplete: Insufficient oxygen, produces CO (toxic) and water.

Polymers

Addition Polymerization

• Chains of monomers forming polymers.
• Example: Ethene to polyethene.
• Biodegradable: Breakdown using microorganisms.

Chemical Tests

Common Tests

• Hydrogen: Lighted splint, squeaky pop.
• Oxygen: Relights glowing splint.
• CO2: Turns limewater cloudy.
• Chlorine: Bleaches damp litmus paper.
• Ammonia: Turns damp red litmus paper blue.

Flame Tests

• Lithium: Red flame.
• Sodium: Yellow flame.
• Potassium: Lilac flame.

Conclusion

• Lecture concludes with summary and mention of additional resources available.