mixtures -- Distillation, chromatography

What is a mixture?

• A substance with only one type of atom.

• It contains two or more different substances physically combined.

• Substances with two or more elements

Oxygen and hydrogen are elements. They are both pure substances.

• True

• False

How does a compound form?

• When two or more substances join together physically.

• When two or more elements combine together chemically.

• It forms with only one kind of atom.

Select the THREE answers which are true for elements.

• have only one kind of atom

• Can be broken down by chemical means

• Cannot be broken down by chemical means

• Made up of more than one kind of molecules

• Has the same properties throughout

Select the THREE answers which are true for Compounds.

• Made up of more than one kind of atoms

• Has different properties from the elements making it up

• Can be separated by physical means

• Has same properties as the substances making it up

• Can be broken down by chemical means

Select the FOUR answers which are true for Mixtures.

• Has different properties throughout

• Cannot be broken down by chemical means

• Has the same properties as the atoms making it up

• Made up of more than one kind of molecules

• Can be separated by physical means

What physical property is used to separate substances in distillation process?

• difference between the evaporation points of the mixed substances

• difference between the boiling points of the mixed substances

• difference between the freezing points of the mixed substances

Which two process are involved in distillation technique?

• Freezing and evaporation

• Evaporation and boiling

• Evaporation and condensation

Liquid "A" has a boiling point of 56 °C and liquid "B" has 78.37 °C. Which of the following method should be used to separate the two liquids?

• Chromatography

• Distillation

• Evaporation

How does the chromatography work?

• It separates solvent from a solution

• When vapour transfers to the condenser.

• Substances separate as they travel in a mobile phases which passes through a stationary phase