Compounds

6.3  Compounds

 

Definition
A compound consists of two or more elements or compound mixed chemically

 Examples: Water, building blocks and tiles

How metal and non-metal elements combine chemically to form compound

magnesium + oxygen \(\rightarrow\) magnesium oxide

aluminium + oxygen \(\rightarrow\) aluminium oxide

zinc + oxygen \(\rightarrow\) zinx oxide

Methods to Separate Compound

  • Compounds cannot be separated physically
  • Therefore, compound can only be separated chemically by electrolysis
Definition
Electrolysis is a chemical decomposition of a compound to its elements by passing an electric current through the compound

 Electrolysis of water

 

  • Water consists of hydrogen and oxygen
  • Therefore, to separate the hydrogen and oxygen from water, the water must undergo the electrolysis process
The differences and similarities between physical and chemical changes
Physical Chemical
Does not form a new substance Forms a new substance that is different from the original substances
Examples: Ice melting, water freezing Examples: Rusting of iron, photosynthesis
The properties of the substances remain same The properties of the substances and poducts are not the same
The chemical composition of the substances remain the same The substances and products have different chemical composition
Needs less energy Needs more energy
Occur to matter
Needs energy

 

The differences between mixtures and compounds
Mixtures Differences Compounds
No Formation of new substances Yes
No Chemical bond Yes
Physical Separation method Chemical
Same Properties of new substances Different

Compounds

6.3  Compounds

 

Definition
A compound consists of two or more elements or compound mixed chemically

 Examples: Water, building blocks and tiles

How metal and non-metal elements combine chemically to form compound

magnesium + oxygen \(\rightarrow\) magnesium oxide

aluminium + oxygen \(\rightarrow\) aluminium oxide

zinc + oxygen \(\rightarrow\) zinx oxide

Methods to Separate Compound

  • Compounds cannot be separated physically
  • Therefore, compound can only be separated chemically by electrolysis
Definition
Electrolysis is a chemical decomposition of a compound to its elements by passing an electric current through the compound

 Electrolysis of water

 

  • Water consists of hydrogen and oxygen
  • Therefore, to separate the hydrogen and oxygen from water, the water must undergo the electrolysis process
The differences and similarities between physical and chemical changes
Physical Chemical
Does not form a new substance Forms a new substance that is different from the original substances
Examples: Ice melting, water freezing Examples: Rusting of iron, photosynthesis
The properties of the substances remain same The properties of the substances and poducts are not the same
The chemical composition of the substances remain the same The substances and products have different chemical composition
Needs less energy Needs more energy
Occur to matter
Needs energy

 

The differences between mixtures and compounds
Mixtures Differences Compounds
No Formation of new substances Yes
No Chemical bond Yes
Physical Separation method Chemical
Same Properties of new substances Different