Chemistry AC2

Mixtures

A combination of two or more substances that are not chemically joined and can be separated

Solutions and solubility

A solution is a mixture where a solute dissolves in a solvent and solubility is how much solute can dissolve

Evaporation and distillation

Evaporation is when a liquid turns to gas and distillation separates liquids by boiling and condensing

Chromatography

A method used to separate dyes or pigments based on how far they travel on paper

Acids and alkalis

Acids have a pH less than 7 and alkalis have a pH more than 7

pH scale and indicators

The pH scale measures acidity and alkalinity and indicators change colour to show pH

Compounds

Substances made from two or more elements chemically bonded together

Mixtures

Substances mixed but not chemically joined and can be separated physically

Chemical reactions

Processes where substances rearrange to form new substances

Formulae and equations

Formulae show what atoms are in a substance and equations show chemical reactions symbolically

Neutralisation

When an acid reacts with an alkali to form salt and water

Reactivity of metals with acids

Metals react with acids to produce a salt and hydrogen gas

Reactions of oxides with acids

Metal oxides react with acids to form salt and water

Solids liquids and gases

The three states of matter with different particle arrangements and movement

Particle theory

Explains matter as tiny particles with spaces and movement

Gas pressure and diffusion

Gas pressure is caused by particles hitting surfaces and diffusion is particles spreading out

Physical changes

Changes of state or form where no new substance is made

Atoms and elements

Atoms are the smallest particles of matter and elements are made of only one type of ato