Purity and formulations

• What is a pure substance in chemistry?

  A substance not mixed with any other substance
• How can melting and boiling points indicate purity?

  They occur at specific fixed temperatures
• What happens to the temperature of a pure substance when it melts?

  The temperature stops rising at the melting point
• What is the melting point of pure water?

  0 degrees Celsius
• What happens to the temperature of pure water when it boils?

  The temperature stops rising at the boiling point
• What is the boiling point of pure water?

  100 degrees Celsius
• How does the graph of a pure substance differ from that of an impure substance?

  Pure substances have fixed melting and boiling points
• What is a formulation in chemistry?

  A complex mixture designed as a useful product
• Why are the quantities of components in a formulation carefully measured?

  To ensure the product has desired properties
• Where can you find questions on pure and impure substances?

  In the revision workbook
• What does a mixture of water and an impurity indicate?

  That the water is not pure
• How do the melting and boiling points of impure substances differ from pure substances?

  They occur over a range of temperatures