Which of the following is not true of a pure substance?
A pure substance is a single element or compound.
A pure substance contains only one type of atom.
A pure substance is not mixed with any other substance.
Which method could be used to separate a mixture of ethanol and water?
Filtration.
Recrystallisation.
Fractional distillation.
What is the definition of ‘solution’?
The liquid in which a solute is dissolved.
A solute dissolved in a solvent.
The substance that dissolves in a liquid.
Distillation involves which physical processes?
Evaporation and condensation.
Melting and freezing.
Dissolving and sublimation.
Higher tier only
In chromatography, what can be used to identify an unknown substance?
Boiling point.
Melting point.
Rf value
Which of the following statements about changes of state is true?
When a solid turns into a liquid this is called freezing.
When a gas turns into a liquid this is called condensing.
When a liquid turns into a gas this is called melting.
What is subliming?
When a solid turns into a liquid.
When a solid turns into a gas and vice versa.
When a gas turns into a liquid.
When sand and water are separated using filtration - what term is used to describe the sand that is left in the filter paper at the end of the separation?
Residue
Filtrate
Distillate
What is he best separating technique to use to separate the colours in food dye?
Filtering
Chromatography
Distillation
Which statement best describes how the particles in a solid are arranged?
The particles are far apart and moving quickly.
The particles are close together and not moving.
The particles are close together and vibrating quickly.