Topc 2- states of matter and mixtures

2.1 Describe the arrangement, movement and relative energy of particles in each of the three states of matter: Solid, liquid and gas.

Solids:

Arrangement: Regular pattern.

Movement: Vibration

Relative energy of particles: Low energy.

Liquids:

Arrangement:

Random

Movement: Move around each other.

Relative energy of particles: Medium energy.

Gas:

Arrangement: Irregular/ random.

Movement: Move freely.

Relative energy of particles: High energy.

2.2 Recall the names used for the interconversions between the three states of matter, recognising that these are physical changes: contrasted with chemical changes that result in chemical changes.

Solid- Liquid- Melting

Liquid- Gas- boiling

Gas- Liquid- condensation

Liquid- solid- Freezing

Solid- Gas- Sublimation

2.3 Explain the changes in arrangement, movement and energy of particles during these interconversions.

Solid- Liquid-Gas Regular- regular pattern to random arrangement to irregular/ Random pattern.

Solid- Liquid- Gas Vibration to move around each other freely to move freely.

Solid- Liquid- Gas Low energy to medium energy to high energy.

2.4 Predict the physical state of a substances under specified conditions, given suitable data

Heating curve-cooling curve.

2.5 Explain the difference between the use of 'pure' in chemistry compared with its everyday use and the differences in chemistry between a pure substances and a mixture.

In everyday usage, a pure substance is a

material that is free of impurities or

contaminants. However, the definition of a

pure substance is more narrow in chemistry.

In chemistry, a pure substance has a

constant chemical composition. No matter

where you sample a substance, it is the same

2.6 Interpret melting point data to distinguish between pure substances which have sharp melting point and mixtures which melt over a range of temperatures.

Impure substance melts over a larger range of temperatures.

Though pure substances melt over defined temperatures.

2.7 Explain the types of mixtures that can be separated by using different experimental techniques.

a.) Simple distillation- Two substances with significantly different boiling points.

b.) Fractional distillation- Two substances that have similar boiling points.

c.)Filtration- Insoluble solid from a liquid.

d.) Crystallisation- Solute (Dissolved Solid) from a solution (solute/ solvent)

e.) Paper chromatography- A mixture of two soluble solids (Solids that dissolve in liquids) substances.

2.8 Describe an appropriate experimental technique to separate a mixture, knowing the properties of

the components Of the mixture.

- Substances with very different boiling points= Simple distillation.

-Substances with similar boiling points= Fractional distillation.

-Insoluble solid from a liquid= Filtration.

-Solute from a solution= crystallisation.

-A mixture of two soluble substances

2.9Describe paper chromatography.

The separation of mixtures of soluble substances by running a

solvent (mobile phase) through the mixture on the paper (the paper contains the stationary phase),

which causes the substances to move at different rates over the paper.

Interpret a paper chromatogram

a.) To distinguish between pure and impure substances.

b.) To identify substances by comparison with known substances.

c.) To identify substances by calculation and use of Rf values.

a.) chromatography separates a mixture of soluble substances. An impure substance will have more chemical components displayed on the stationary phase.

b.) Which soluble substances are displayed and compare to known substances.

c.)Rf Value= Solute distance/ Solvent distance. Have to be 0-1.

2.11 Core Practical: Investigate the composition Of inks using simple distillation and paper

Chromatography.

……

2.12Describe how:

a.) waste and ground water can be made potable, including the need for sedimentation,

filtration and chlorination;

b.) sea water can be made potable by using distillation;

c.) water used in analysis must not contain any dissolved salts.

a.) Ground water contains; small leaves, silt and grit, salts, pesticides, fertilizers, bacteria and microorganisms. Sedimentation- solid settling to the bottom in solution.

Filtration- Solution is passed through filters to separate solid residue and the filtrate. Chlorination- Add chlorine to the solution to kill the bacteria.

b.) Use simple distillation to extract the solvent (Water) from the salt (solute) in solution. The water will evaporate, leaving behind the salt. Uses evaporation and condensation to create a pure substance.

PPQ: Why might the simple distillation of sea water be used to provide drinking water in oil-rich coastal countries? This is because it is likely there is an excess of sea water and oil; the oil can be used to heat the solution. The water can also be collected from the sea and be heated by the oil.

c.) Interfere with the sensitivity of the tests.

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