Patterns of Reactivity & Salt Preparation (IGCSE Chemistry Ch. 9-11)

Vocabulary flashcards covering key terms from Chapters 9-11 on energy changes, combustion, metal reactions, and salt preparation.

Endothermic Reaction

A chemical change in which heat is absorbed from the surroundings, causing the surroundings to become cooler.

Exothermic Reaction

A chemical change that releases heat to the surroundings, making them warmer.

Complete Combustion

Burning a hydrocarbon in plentiful oxygen to form carbon dioxide and water and release heat and light.

Incomplete Combustion

Burning a hydrocarbon with limited oxygen, producing carbon monoxide (and sometimes soot) plus water.

Carbon Monoxide (CO)

Toxic gas formed in incomplete combustion; binds to haemoglobin more strongly than oxygen and can be lethal.

Hydrocarbon

Compound made only of carbon and hydrogen atoms, e.g., CH₄, used as fuels in combustion reactions.

Synthesis Reaction

A reaction in which two or more reactants combine to form one product (e.g., metal + oxygen → metal oxide).

Single Replacement (Displacement) Reaction

Reaction where an element replaces another element in a compound, forming a new element and compound.

Metal Oxide

Compound consisting of metal atoms bonded to oxygen; many act as alkalis and react with acids to form salts and water.

Metal Hydroxide

Compound containing a metal ion bonded to hydroxide ions (OH⁻); if soluble, it forms an alkali solution.

Alkali

A soluble base that produces hydroxide ions (OH⁻) in water, turning litmus blue and neutralising acids.

Metal Displacement Reaction

Process in which a more reactive metal displaces a less reactive metal from its compound.

Reactivity Series

Ordered list of metals from most to least reactive, used to predict displacement reactions and extraction methods.

Metal Carbonate

Compound containing metal cations bonded to carbonate ions (CO₃²⁻); reacts with acids to give salt, CO₂, and water.

Carbonic Acid (H₂CO₃)

Unstable acid briefly formed when metal carbonates react with acids; quickly decomposes to CO₂ and H₂O.

Neutralisation

Reaction between an acid and an alkali (or base) to produce a salt and water.

Titration

Analytical technique that measures the exact volume of one solution needed to react completely with another, often using an indicator.

Binary Salt

Salt composed of only two different elements; named by writing the metal first and non-metal with the ending “-ide.”

Sulphate Salt

Salt containing the SO₄²⁻ ion, produced when sulphuric acid reacts with a base or metal.

Chloride Salt

Salt containing the Cl⁻ ion, produced when hydrochloric acid reacts with a base or metal.

Nitrate Salt

Salt containing the NO₃⁻ ion, produced when nitric acid reacts with a base or metal.

Limewater Test

Method for detecting carbon dioxide; CO₂ turns clear calcium hydroxide solution milky.

Squeaky Pop Test

Test for hydrogen gas; a lit splint placed near the gas produces a characteristic pop sound.

Oxidation (Combustion Context)

Reaction in which a substance combines with oxygen, often releasing energy as heat and light.

Photosynthesis

Endothermic biological process where plants absorb light energy to convert CO₂ and water into glucose and O₂.

Respiration

Exothermic biological process in which glucose is oxidised to release energy, CO₂, and water.

Hand Warmers

Commercial devices that utilise exothermic reactions (e.g., iron oxidation) to produce heat.

Buret

Precision glass tube with a tap, used in titration to dispense measured volumes of solution.