maintaining air quality

• air composition of argon gas

  1%
• air composition of carbon dioxide

  0.03%
• air is a mixture
• steps for separating air by fractional distillation

  1. air is first cooled and compressed into liquid state
  2. water vapour is removed by filtration as a solid (ice)
  3. carbon dioxide is removed by filtration as a solid (dry ice)
  4. remaining components of air are separate by fractional distillation
• how to determine composition of oxygen in syringe (copper turnings)

  heat the copper turnings and it will react with oxygen to form copper (II) oxide

  brown turnings will become black
• determining composition of oxygen with iron fillings

  moist iron fillings reacts with oxygen to form iron (III) oxide

  grey fillings turns brown

  water level rises to take the place of oxygen lost
• source of carbon monoxide

  incomplete combustion of carbon containing substances such as petrol
• effect of carbon monoxide

  reduce oxygen in blood and forms stable compound with red blood cells
• source of nitrogen oxide

  natural: lightning activity

  internal combustion in car engines at high temperature when nitrogen and oxygen reacts
• effect of nitrogen oxide and sulfur dioxide

  dissolves in rain to form acid rain which corrodes metal structures and limestone buildings

  acid rain lowers the pH of plants and takes the nutrients out of the soil which is why plants are unable to grow healthily
• effect of sulfur dioxide


  cause breathing problems
• source of sulfur dioxide

  natural: volcanic eruptions

  combustion of fossil fuels in power stations
• source of methane (CH4)


  bacterial decay of organic substances

  animals give off methane gas due to food digestion
• effect of methane


  it is a greenhouse gas and can cause greenhouse waste
• source of unburnt hydrocarbons

  vehicle combustion engines
• effect of unburnt hydrocarbons


  can cause eye and respiratory problems

  it reacts with nitrogen oxide in sunlight to form brown haze
• source of ozone


  react with nitrogen oxide and unburnt hydrocarbons in sunlight

  lightning
• effect of ozone


  cause breathing difficulties and eye problems
• how to reduce carbon monoxide and nitrogen oxides from car engines?

  cars are fitted with catalytic convertors
• how to remove sulfur dioxide from power stations?

  pass gas to calcium carbonate to form calcium sulfite
• rainwater typically has a pH between 5 -5.5 due to naturally occurring oxides dissolving in rainwater
• acid rain


  corrodes metal and dissolve in stone
• negative effects on acid rain

  acid rain takes out nutrients from the soil which hampers the health of trees. acid rain lowers the pH of soil and can kill species that live in them
• negative effects on acid rain


  aquatic organisms are very sensitive to pH changes, too acidic can kill them
• what is the carbon cycle?

  carbon dioxide is a greenhouse gas that contributes to global warming. it describes how carbon containing compounds are converted from one form to another. carbon moves between the atmosphere, lands or even living creatures
• processes that release carbon dioxide into the atmosphere

  respiration

  combustion of fuel

  bacterial decomposition
• process that removes carbon dioxide from the atmosphere

  photosynthesis, ocean uptake
• how is carbon dioxide exchanged through photosynthesis

  plants remove carbon dioxide from the atmosphere
• how is carbon dioxide exchanged through respiration?

  animals eat plants which releases carbon dioxide into the atmosphere
• how is carbon dioxide exchanged through combustion

  humans burn fossil fuels which releases carbon dioxide
• how is carbon dioxide exchanged through decomposition?

  ancient animals and plants eventually become fossil fuel
• how is carbon dioxide exchanged through ocean uptake

  sea creatures build their shells from dissolved carbonates and these carbonates form limestone
• examples of greenhouse gas

  methane and carbon dioxide
• what is meant by greenhouse gas?

  it is any gas compound in the atmosphere that is capable of absorbing infrared which traps heat in the atmosphere
• how does global warming occur?

  due to various activities, the amount of greenhouse gas released to the atmosphere increased greatly. greenhouse gases build up rapidly in the atmosphere
• change in rainfall patterns and its consequences

  temperature rising can lead to changes in rainfall patterns. some areas might receive too little rain and become deserted while other areas might receive too much rain. deserted area may no face food shortage as they cannot produce them without rain
• heat waves and its consequences

  heat waves can make destructive wildfires more commons and could destroy ecosystems
• tropical storms and its consequences

  tropical storms like hurricanes form over warm water and can be very destructive. it can endanger human lives and destroy property. the warmer the ocean, the stronger these storms grow
• ocean warming and its consequences

  marine organisms can be very sensitive to water temperatures. rising temperatures can cause coral reefs to die

  warmed ocean waters also absorb carbon dioxide more quickly forming acid which can lower the pH of the water. acid waters can remove carbonate minerals from crabs which depends on it to form their shells
• aquatic organisms are very sensitive to pH change. when acid rain falls into a water body, the pH level of the water body can fall below survival range