Developing fuels!

Question 1

experiments to measure the energy transferred when flammable liquids burn

Answer 1

• Measure known
  volume of water, add
  to copper
  calorimeter, clamped
  above spirit burner
• Measure temp of
  water
• Weigh spirit burner
• Light wick, wait unit
  temp of water rises
  by approx. 15oC
• Extinguish flame,
  record temp again
• Re-weigh spirit
  burner

Question 2

Reasons why experimental results are different to theoretical values:

Answer 2

• Not done in standard conditions
• Heat loss
• Incomplete combustion

Question 3

experiments to measure the energy transferred when reactions occur in
solution

Answer 3

• Add one solution
  to insulated cup.
• Record temp
  every 30 seconds
  for several
  minutes
• Add the other
  solution (or
  solid), stir
• Continue to
  record temp
  every 30 seconds
  for approx. 15
  minutes
• Plot graph of
  temp vs time.
• Use graph to
  determine
  temperature
  change

Question 4

techniques and procedures for cracking a hydrocarbon vapour over a heated catalyst and testing the product

Answer 4

• heat the catalyst strongly
• heat the hydrocarbon gently collecting the gas that forms in the upturned
  test tube
• discard the first tube as this will just contain air
• Continue heating until you have colected several tubes
• Stopper the tubes
• Add bromine water – the gases in the tubes should decolorise the bromine
  water, as alkenes have been formed

Question 5

addition reactions of alkenes with hydrogen in the presence of a catalyst to give an alkane (Ni with heat and pressure
or Pt at room temperature and
pressure)

Answer 5

• Ni catalyst, 150OC, 5 atmospheres of pressure
• Or Pt catalyst at room temperature and pressure
• Pt is a more efficient but much more expensive catalyst
• Heterogeneous catalysis