Please enable JavaScript.
Coggle requires JavaScript to display documents.
C1.1-C1.4 (Chemical Equations (Law of conservation of mass (The Law of…
C1.1-C1.4
Chemical Equations
Chemical equations show the reactants (substances you start with) and the products (the new substances made) in a reaction.
-
In chemical reactions the atoms get rearranged. Symbol equations show the numbers and types of atoms in the reactants and the products.
Atoms are neither created or destroyed in a chemical reaction. So the number and type of atoms remains the same before and after the reaction.
When writing symbol equations you should always make sure it is a balanced equation. A balanced symbol equation has the same number of each type of atom on both sides of the equation. Use multiplier (placed in front of the formulae) to ensure symbol equations balance.
You can include state symbols in balanced symbol equations. These are (s), (l), (g) or (aq) - solids, liquids, gases, and aqueous solutions.
-
Atoms
There are about 100 different elements from which all substances are made. The periodic table is a list of all these elements.
-
Atoms are represented by chemical symbols, e.g. Na for an atom of sodium, O for an atom of oxygen.
The elements in the periodic table are arranged in columns, called groups. The elements in a group usually have similar properties.
-
When elements react, their atoms join with atoms of other elements. Compounds are formed when two or more elements combine together.
-
Separating Mixtures
A mixture made up of two or more substances (elements or compounds) that are not chemically combined together. The chemical properties of each substances is unchanged.
Mixtures are separated by physical processes. Physical processes do not involve chemical reactions, so no new substances are made. Physical processes include:
Filtration: separates substances insoluble in a solvent from those that are soluble in the solvent. For example, sand can be separated from salt solution using filtration.
Crystallisation: separates a soluble solid from a solvent, for example, salt from salt solution.
Distillation: separates a solvent from soluble solids dissolved in the solvent. For example, seawater is distilled to obtain usable water.