Change of state

• What units are used for temperature in change of state?

  degree Celsius (°C), joule (J), kilogram (kg)
• What happens when a system is heated?

  Energy stored changes and temperature rises
• What occurs when a solid melts?

  It forms a liquid
• What happens when a liquid evaporates?

  It forms a gas
• How are particles arranged in solids?

  They are closely packed in a fixed arrangement
• How do particles move in liquids?

  They are close but can slide past each other
• How do particles behave in gases?

  They move freely and are far apart
• What does a temperature-time graph show during a change of state?

  Constant temperature during the change
• What is specific heat capacity?

  Energy required to change temperature by 1°C
• What is the equation for change in thermal energy?

  ΔQ = m × c × ΔT
• How can specific heat capacity be investigated practically?

  By measuring temperature changes in materials

  
  

  
  

  
  

  1. Place the ice cubes in the beaker (it should be about half full)
  2. Place the thermometer in the beaker
  3. Place the beaker on the tripod and gauze and slowly start to heat it using the bunsen burner
  4. As the beaker is heated, take regular temperature measurements (e.g. at one minute intervals)
  5. Continue this whilst the substance changes state (from solid to liquid)