PAST PAPER Q'S

• explain how carbon monoxide produced which petrol is burned in car engines

  carbon monoxide is produced by incomplete combustion, insufficient oxygen
• suggest two reasons why maximum allowed percentage of carbon monoxide has been decreased for newer cars

  its poisonous

  awareness about pollution
• give one reason for having maximum allowed percentage of unburned hydrocarbons in exhaust fumes

  to reduce health problems
• describe how oxides of nitrogen are produced when petrol is burned in car engines

  nitrogen from atmosphere reacts with oxygen from atmosphere at high temps
• give two effects of atmposheric pollution which are reduced by using catalytic converts

  acid rain

  respiratory problems
• sulfur produces a gas that causes acid rain

  what is the gas

  sulfur dioxide
• give one environment effect caused by acid rain

  damage to limestone buildings
• carbon monoxide is a toxic gas

  give two reasons why people may be unaware of the presence of carbon monoxide

  its odourless

  its colourless
• why is it important that sulfur dioxide is not realised into the atmosphere

  sulfur dioxide causes acid rain
• what colour is universal indicator in a solution of sulfur dioxide

  give reason for answer

  red

  because when sulfur dioxide is in a solution it is acid
• Sulfur dioxide is a gas at room temperature

  The bonding in sulfur dioxide is covalent

  Explain, in terms of its structure and bonding why sulfur dioxide has a low boiling point


  has weak forces of attraction between molecules

  take little energy to overcome
• explain why the clearing of large areas of forest has an environmental impact on the atmosphere

  increase greenhouse effect

  less CO2 is absorbed from atmosphere
• why is there an increasing demand for biodiesel


  crude oil is running out/ non-renewable
• Suggest why producing biodiesel from crops
• name the substance removed fro seawater by desalination

  salt
• desalination is only used when there is no other source of potable water

  expensive
• why is water filtered


  to removed solids
• why is chlorine gas used to treat water

  Sterilise water
• describe test for chlorine gas


  damp litmus paper

  bleached
• what are two main steps used to treat water from lakes

  STEP 1: filtration, to remove solids

  STEP 2: sterilise, to kill microbes
• explain why it is more difficult to produce drinking water than from water in lakes

  water needs different processes

  it contains microbesSee an expert-written answer!We have an expert-written solution to this problem!
• how could water be tested to show its pure

  give the expected result of the test for pure water

  determine boiling point

  should be at fixed temperatures
• why is producing drinking water from sea water expensive?

  uses large amounts of energy
• what is removed when water is filtered

  solids
• why is water sterilised

  to remove microbes
• distillation is expensive because it requires lots of

  energy
• why do some water companies add fluoride to drinking water

  improve dental health
• what two main steps used to treat water from reservoirs

  filter to remove solids

  add chlorine to remove microbes
• what is in water filters that removes hardness from water

  ion exchange resin
• Suggest why water filters used in the home contain particles of silver

  prevent growth of microbes
• explain why it is more difficult to produce drinking water from waste water then from water in lakes


  water needs different processes

  it contains microbes
• how could the water be testes to show its pure

  determine boiling point

  should be at fixed temperature
• Why is producing drinking water from sea water expensive?

  lots of energy required
• state one health benefit of drinking hard water


  helps develop bones
• what is the boiling point of pure water

  100 C
• what piece of apparatus would be suitable for measuring 25cm of sea water

  measuring cylinder
• how could the student check that all the water is evaporated

  reheat the evaporating dish

  weigh again
• why is chlorine added to drinking water

  kill bacteria
• the amount of chlorine in swimming poll should be carefully monitored and controlled why


  chlorine is toxic

  too much can be dangerous
• suggest why people from all political parties should be represented when a government is setting up an enquiry into the safety of using chlorine

  so it is fair