Possible exam qs

• Explain why the apparatus must be air tight?

  • To prevent air entering and leaving
  • Which will affect pressure & volume
  • Which will affect distance moved by coloured liquid
• Explain the purpose of soda lime

  • To absorb CO2 produced
  • So only vol of O2 absorbed by maggots is measured
• Whats the equation for rate ? and how do we calculate vol?

  Rate = vol/tm

  Vol of cylinder = $\pi$r$^2$h

  (h is distance moved)
• State the units for respiration in this experiment

  cm$^3$min$^{-1}$g$^{-1}$