Potable water

• What is potable water?

  Water that is safe to drink
• How can we obtain potable water?

  By treating fresh water or desalinating seawater
• What does it mean for water to be pure in chemistry?

  It contains only H2O molecules
• What makes potable water impure?

  Presence of other dissolved substances
• What are the three criteria for water to be considered potable?

  Low dissolved substances, pH 6.5-8.5, no microorganisms
• Why is pH important for potable water?

  To ensure it is not too acidic or alkaline
• What are surface water sources?

  Lakes, rivers, and reservoirs
• How is groundwater defined?

  Water found under the ground in aquifers
• What is a benefit of using surface water?

  It is easy to access and replenished by rain
• What is a disadvantage of surface water in hot weather?

  It can dry up due to sun exposure
• What is the first step in treating fresh water?

  Filtering through a wire mesh
• What is the second step in treating fresh water?

  Passing it through sand and gravel
• What is the final step in treating fresh water?

  Sterilizing to kill harmful microbes
• What are three methods to sterilize water?

  Chlorine gas, ozone, ultraviolet light
• Why do some countries rely on desalination?

  They have limited fresh water supply
• What is the main challenge of desalination techniques?

  They require a lot of energy and are expensive
• How does distillation work in desalination?

  Boiling salty water and condensing vapor
• What happens in reverse osmosis desalination?

  Salty water passes through a selective membrane
• What is the result of both distillation and reverse osmosis?

  Pure distilled water
• What are the steps involved in treating fresh water to make it potable?

  1. Filter through a wire mesh
  2. Pass through sand and gravel
  3. Sterilize to kill harmful microbes
• What are the differences between surface water and groundwater sources?

  • Surface water:
  • Found above ground (lakes, rivers)
  • Easy to access
  • Replenished by rain
  • Groundwater:
  • Found underground (aquifers)
  • More stable in hot weather
  • Requires drilling to access
• What are the strengths and weaknesses of desalination techniques?

  Strengths:

  • Provides a source of potable water
  • Useful in arid regions

  
  

  Weaknesses:

  • High energy consumption
  • Expensive to implement