1.1 Introduction to the particulate nature of matter and chemical change

States of matter

• Everything is made up of matter. The characteristics of matter are:
  • Made up of particles – atoms, molecules or ions
  • Particles are in constant motion
  • Occupies a volume in space
  • Has a mass

Properties of three states of matter

Temperature

• The vibration and movement of particles depend on temperature
• As temperature increases, KE_avg increases
• The SI unit for temperature is the kelvin (K)
• Absolute zero is 0 on the kelvin scale (-273° on Celsius scale), and is the temperature at which all movement of particles stops
• Temperature (K) = Temperature (°C) + 273.15

Changes of State

• Take water for example:

• As temperature increases, kinetic energy in particles increase, causing change of state
  • Melting and boiling are endothermic reactions – energy is transferred from environment
• As temperature decreases, kinetic energy decreases, causing reversal of state
  • Condensation and freezing are exothermic reactions – energy is transferred to environment
• There is no change in temperature while melting, boiling, condensing or freezing,
• energy is used to break/create attractive forces so change of state can occur
• Changes of state can be described using the following terms:

 

Classification of Matter

 

• Ion: A charged species
• Anion: Negatively charged ion
• Cation: Positively charged ion

How to balance equations

• Watch this video

4 types of chemical reactions

1. Synthesis
2. Decomposition
3. Single Displacement
4. Double Displacement
   1. Complete Combustion
   2. Incomplete Combustion

State symbols

1. (s) – solid
2. (l) – liquid
3. (g) – gas
4. (aq) – aqueous

The Atom Economy

• Is a measure of the amount of starting materials that become useful products.
• High atom economy means that less waste is created and reaction has a high efficiency
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