potato experiment required practical

• What is the method for the potato experiment?

  • First peel potato
  • Use cork borer to make 3 cylinders
  • Use a scapel to trim cylinders to same length
  • Measure the mass and length of them using ruler and balance
  • Place each cylinder into a test tube
  • Add 10cm of 0.5 molar sugar solution to first tube
  • Add 10cm of 0.25 molar sugar to 2nd tube and water to 3rd
  • Leave overnight
  • Remove potato and rub in potato towel
  • Measure length and mass again
  • Use this equation next:

  
• Why do you dry the potato?

  So liquid left on outside of potato wont affect the mass
• Explain why potato pieces at 0.4 mol salt solution decreased in mass?

  Water moves out by osmosis

  Because solution is less concentrated than the outside
• What was the dependent variable in the experiment?

  The mass of the potato
• What was the independent variable?

  The mole concentration
• Give 2 control variables?

  Volume of solution, temperature and time
• What of water happens when a cell is short ?

  Solution inside becomes concentrated, outside solution will be dilute so water moves in side via osmosis
• What is osmosis?

  Osmosis is the movement of water molecules from an area of low concentration to an area of high concentration across a partially permeable membrane.