ALL Chemistry Factual Recall

Edexcel IGCSE, made with claude

Solid

Particle arrangement

Particles tightly packed, fixed shape, low energy

Liquid

Particle arrangement

Particles close but able to flow, no fixed shape

Gas

Particle arrangement

Particles far apart, moving fast, high energy

Melting

Solid → liquid

Freezing

Liquid → solid

Evaporation/Boiling

Liquid → gas

Condensation

Gas → liquid

Sublimation

Solid → gas

Solvent

Substance that dissolves a solute

Solute

Substance dissolved in a solvent

Solution

Mixture of solute + solvent

Saturated solution

Maximum solute dissolved

Solubility - measured in:

g of solute per 100 g of solvent

Simple distillation

Separates solvent from solution

Fractional distillation

Separates liquids by boiling point

Filtration

Separates insoluble solid from liquid

Crystallisation

Obtains soluble solid from solution

Paper chromatography

Separates soluble substances

Rf value

Distance travelled by substance ÷ distance travelled by solvent

Reason for similarities within groups in a pTable

Same number of outer electrons

Noble gases reactivity

Unreactive due to full outer shell

Metals

Conduct electricity, form basic oxides

Silver ion

Ag⁺

Copper(II) ion

Cu²⁺

Iron(II) ion

Fe²⁺

Iron(III) ion

Fe³⁺

Lead(II) ion

Pb²⁺

Zinc ion

Zn²⁺

Hydrogen ion

H⁺

Hydroxide ion

OH⁻

Ammonium ion

NH₄⁺

Carbonate ion

CO₃²⁻

Nitrate ion

NO₃⁻

Sulfate ion

SO₄²⁻

Ionic compounds properties

High mp/bp, conduct when molten/aqueous

Simple covalent properties

Low mp/bp, no conductivity

Giant covalent properties

Very high mp/bp

Diamond

Hard, no conductivity

Graphite

Conducts, soft/slippery

C60 fullerene

Low mp, molecular

Anion

Negative ion → anode

Cation

Positive ion → cathode

Reaction at cathode

Reduction

Reaction at anode

Oxidation

Conductivity of ionic compounds

Only when molten/aqueous

PbBr₂ electrolysis

Pb at cathode, Br₂ at anode

Aqueous NaCl electrolysis

H₂ at cathode, Cl₂ at anode, NaOH produced

Dilute H₂SO₄ electrolysis

H₂ at cathode, O₂ at anode

CuSO₄ electrolysis

Cu at cathode, O₂ at anode

General reaction: metal + water—> ?

metal hydroxide + hydrogen

Reactivity trend Group 1

Increases down group

Lithium with water observation

Steady fizzing

Sodium with water observation

Fast fizzing, melts

Potassium with water observation

Lilac flame

Reactivity explanation group 1

Outer electron further → more easily lost

Chlorine appearance

Pale green gas

Bromine appearance

Orange

Iodine appearance

Grey solid, purple vapour

Reactivity trend Group 7

Decreases down group

Displacement rule

More reactive halogen displaces less reactive halide

Nitrogen % in air

78%

Oxygen % in air

21%

Argon % in air

1%

CO₂ % in air

0.04%

Mg + O₂

Forms white MgO

Hydrogen + oxygen

Forms water

Sulfur + oxygen

Forms SO₂

Greenhouse gas

CO₂, Methane, SO2

contributes to climate change

Thermal decomposition of carbonates

Metal + carbonate —>

Metal oxide + CO₂

Reactivity series

K > Na > Li > Ca > Mg > Al > Zn > Fe > Cu > Ag > Au

Rusting conditions

Oxygen + water

Rust prevention (barrier)

Paint, grease

Rust prevention (galvanising)

Zinc coating

Rust prevention (sacrificial)

More reactive metal

Oxidation

Gain of oxygen / loss of electrons

Reduction

Loss of oxygen / gain of electrons

Oxidising agent

Causes oxidation, is reduced

Reducing agent

Causes reduction, is oxidised

How are most metals obtained

Extracted from ores

Unreactive metals found:

Found as elements

Iron extraction

Carbon reduction

Aluminium extraction

Electrolysis

Alloy

Mixture of metals

Why are alloys harder

Layers distorted by different atom sizes

Mild steel

Malleable/flexible

High carbon steel

brittle

Stainless steel

Corrosion resistant

Litmus

Red in acid, blue in alkali

Phenolphthalein

Colourless in acid, pink in alkali

Methyl orange

Red in acid, yellow in alkali

Strongly acidic pH range

0-3

weakly acidic pH

4-6

Neutral pH

7

weakly alkaline

8-10

strongly alkaline pH

11-14

Acid

Source of H⁺

Alkali

Source of OH⁻

Acid definition

Proton donor

Base definition

Proton acceptor

All nitrates

Soluble