National Chemistry

 

These notes are for the Scottish National Chemistry course taught in fourth year in most Scottish schools.

 

The notes available here are concise notes. They are NOT to be considered as material to learn from - they are for revision.

 

 The notes are arranged under the following topics

 

Unit 1                        Reaction Rates and the Periodic Table,

                                  Bonding

                                  Acids

 

Unit 2                            Fuels and Hydrocarbons

                                      Carbohydrates

 

Unit 3                                  Metal Chemistry

                                           Nitrogen

 

Hidden in the summary notes are links to websites offering further explanations, animations or videos

National 3

 

When two substances come together without reacting, then a mixture is formed.

Mixtures can be easily separated by physical methods such as filtration and evaporation depending on their solubility.

 

Chemicals can exist as solids (s), liquids (1), or gases (g)

 

At the melting point a chemical changes from solid to liquid

At the boiling point  a chemical changes from liquid to gas

 

 

There are 114 different elements

Each element is made of the same type of atom.  Oxygen is made from oxygen atoms, only.

 

A compound is made from different types of atoms. hydrogen oxide is made from oxygen atoms and hydrogen atoms bonded together.

 

Rate of Reactions

 

Examples of reactions:  iodine clock       decomposition      x

 

Chemical reactions can be identified by

       (i) a change in appearance of substance  

      (ii) a detectable energy change

     (iii) the formation of at least one new substance

 

A solution is formed when a solute dissolves in a solvent.

 

eg salt solution is formed when salt (solute) dissolves in water (solvent).

 

If a solution has a lot of solute dossolved is it said to be concentrated while one with only a little solute dissolved is called dilute. Think about 'concentrated' orange juice that you add water to (to dilute it) before drinking it.

 

If no more solute can dissolve then the solution is said to be saturated.

 

Chemists have classified elements by their chemical properties and arranged them in the Periodic Table in groups (columns) of elements with similar chemical properties.

 

Elements that conduct electricity when  are called metals while elements that do not conduct electricity are called non-metals.

However, carbon in the form of graphite is a non-metal that can conduct electricity

 

Compounds ending in "ide" usually have two different elements present, while

compounds ending in "ite" or "ate" have oxygen as a third element present.

 

eg magnesium sulphide is made of magnesium atoms and sulphide atoms bonded together

copper carbonate is made from copper atoms and carbon atoms and oxygen atoms bonded together

 

Chemical reactions can be illustated as word equations.

eg carbon dioxide and water react in photosynthesis to produce glucose and oxygen can be written as

 

carbon dioxide  +  Water ---> glucose   +   oxygen

National 3

Unit 1