Inorganic chemistry - IGCSE Flashcards
Acid
Produces H+ ions in aqueous solutions
They have a pH range between 0 and 7
Acids are known as proton donors
Base
A substance which reacts with an acid in a neutralisation reaction to form a salt and water only
Bases are known as proton acceptors
Alkali
Produces OH- in aqueous solutions
They have a pH range between 7 and 14
Alkalis are soluble bases
Alloy
A metal compound made by combining two or more metals together
This process is carried out to give greater strength or resistence to corrosion
Ores
A type of rock which contains metals compounds
The metals or metal compounds are present in sufficient amounts to make it worth extracting them
Combustion
The burning of a substance in oxygen
If there is sufficient oxygen present for the substance to burn then it is called complete combustion
Energy is transferred to the surroundings as heat and light
Thermal decomposition
The breaking down of a compound by heating
Corrosion
The destruction of materials by chemical reactions with substances in the environment
Displacement
A chemical reaction in which a more reactive element displaces a less reactive element from its compound
Neutralisation
The reaction in which an acid and a base react to form a salt and a water
Greenhouse effect
The increase in the temperature of the Earth’s atmosphere due to the greenhouse gases in the atmosphere trapping infra-red radiation from the surface
Greenhouse gases
Gases in the atmosphere which mantain temps on Earth high enough to support life
Greenhouse gases include water vapour, CO2 and methane
Oxidation
Gain of oxygen or loss of electrons
Oxidising agent
A species which brings about oxidation by gaining electrons
The oxidising agent itself is reduced
Reduction
Loss of oxygen or gain or electrons
Reducing agent
A species which brings about reduction by losing electrons
The reducing agent itself is oxidised
Redox reaction
A reaction in which both oxidation and reduction occur
Reduction with carbon
Process used to extract metals from their oxides when the metal is less reactive than carbon
The metal oxide is heated with carbon so it reduces the metal oxide to the metallic element
pH scale
A measure of the acidity or alkalinity of a solution ranging from 0 to 14
The pH can be measured using universal indicator or a pH probe
Indicators
A chemical used to distinguish between acidic and alkaline solutions
Examples include phenolphthalein, litmus and methyl orange
They are also used in titration reactions to indicate the end point of the reaction by a clear colour change
Universal indicator
A mixture of dyes that changes colour gradually over a range of pH and is used in testing for acids and alkalis
Rust
Reddish coating of iron oxide which forms on iron when it undergoes oxidation
Iron rusts when it is in the presence of oxygen and water
Galvanise
A process used to protect against corrosion by coating the metal with a protective layer of zinc
Sacrificial protection
The protection of iron or steel against corrosion by using a more reactive metal
Zinc is often used as a sacrificial metal
Sacrificial protection creates a physical barrier to oxygen and water, preventing corrosion of the metal
