Elements, Compounds And Mixtures

Front 1

What is an element?

Back 1

A substance that consists of only one type of atom. It cannot be broken down into a simpler substance by chemical means.

Front 2

What is a compound?

Back 2

A substance that consists of two or more different elements chemically bonded together.

Front 3

What is a mixture?

Back 3

Two or more substances that can be easily separated

Front 4

Define soluble

Back 4

describes a substance that dissolves, eg. salt will dissolve in water.

Front 5

Define insoluble

Back 5

describes a substance that does not dissolve, eg. sand will not dissolve in water.

Front 6

Define solute

Back 6

a substance that dissolves in the solvent, generally referring to a solid but can be a gas, eg. salt is the solute because it dissolves in water.

Front 7

Define solvent

Back 7

a liquid that dissolves the solute, eg. water is the solvent because it dissolves the salt.

Front 8

Define solution

Back 8

a mixture of dissolved solute and solvent, eg. salt dissolved in water gives a salt solution.

Front 9

Define residue

Back 9

the material left after distillation, evaporation, or filtration.

Front 10

Define filtrate

Back 10

a liquid that has passed through the filtration process.

Front 11

Define distillate

Back 11

the vapour in a distillation that is collected and condensed into a liquid.

Front 12

Define miscible

Back 12

If two liquids dissolve in each other they form a single continuous layer.

Front 13

Define immiscible

Back 13

Liquids that are not soluble in each other form two distinct layers.

Front 14

Explain filtration

Back 14

This separates the liquid and the insoluble solid. The liquid passes through tiny pores in the filter paper. The insoluble grains are to big to pass through. The insoluble solid stays on the paper.

Front 15

Explain evaporation

Back 15

This separates the solute from the solvent. The solvent is evaporated and escapes into the air. The solute is left in the evaporating basin.

Front 16

Explain chromatography

Back 16

This separates the components of a mixture in a solution using differences in their solubility in a solvent.

Front 17

Physical properties of metallic elements (9 points)

Back 17

Shiny, usually high melting and boiling points, high density, malleable, ductile, conducts heat, conducts electricity, hard, sonorous

Front 18

Physical properties of non-metallic elements (8 points)

Back 18

Usually dull, usually low melting and boiling points, low density, brittle, soft (except gold), poor conductors of heat, do not conduct electricity (except graphite), non-sonorous

Front 19

Physical properties of compounds

Back 19

Different to those of the elements that make up the compound, the composition is always the same

Front 20

Physical properties of mixture

Back 20

The same as those of the elements that make up the mixture, the composition can vary,

Front 21

What happens when a compound is formed?

Back 21

A chemical reaction takes place and there is an energy change

Front 22

What is mass spectrometry used for?

Back 22

To determine the RAM and RMM.

Front 23

How does mass spectrometry work?

Back 23

By accurately comparing the masses of the atoms and molecules, atoms are too 'small' to be weighed on normal lab balances.

Front 24

What is high performance liquid chromatography?

Back 24

A technique used to separate mixtures of volitile liquids into their individual components. Once separated it is possible to identify what these components are. Often necessary to combine this technique with another eg. mass spectrometry to get a complete identification of the substance.

Front 25

What are the benefits of mass spectrometry and high performance liquid chromatography?

Back 25

Fast results, only small samples needed.

Front 26

What are the drawbacks of mass spectrometry and high performance liquid chromatography?

Back 26

Needs trained analytical chemist, expensive.

Front 27

What are the risks of mass spectrometry and high performance liquid chromatography?

Back 27

Potentially dangerous chemicals, chemicals could be tampered with.