Osmosis Lab

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Osmosis Lab
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Definition of Osmosis

• WATER moves from an area of HIGH to LOW
  concentration.

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Problem/Purpose

• What effect will distilled water and salt water
  have on the mass of a potato slice?
• Increase in mass water going in
• Decrease in mass water coming out

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ResearchBackground Knowledge

• Osmosis is the diffusion of water.
• Water moves from an area of high to low
  concentration.
• The size of the substance in relationship to the
  size of the openings (pores) in the membrane will
  impact diffusion/osmosis.
• Cells will either remain the same, swell or
  shrink as a result of osmosis.

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Hypothesis

• The potato slice in the distilled water will
  increase in mass.
• The potato slice in the distilled water will
  decrease in mass.
• The potato slice in the salt water will increase
  in mass.
• The potato slice in salt water will decrease in
  mass.
• DONT FORGET YOUR REASONING . . . YOUR BECAUSE
  STATEMENT.

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Variables

• Independent
• What did we change? What experimental condition
  was under our control?
• Type of Water

• Dependent
• What are we measuring? What data we are
  collecting?
• Mass of the potato slice

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The Experiment

• Control Group
• Did we have one?
• Potato slice placed in an isotonic solution
• No movement of water
• Potato in distilled water

• Experimental Group
• Potato in salt water

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Constants

• What did we keep the same to control the number
  of variables introduced into the experiment?
• The potato
• Volume of liquid in Petri dish
• Equipment as directed in Materials list
• Method used to set up the experiment
• Method used to collect data

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The Data
Type of Water Mass Before (grams) Mass After (grams) Difference in Mass (grams) increase or decrease


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of Change(increase or decrease)

• Difference Mass Before 100
• Mass Before 4 grams
• Mass After 6 grams
• Difference in Mass 2 grams
• 2 g 4 g 0.50 100 50