3.2.1 Investigating Osmosis

• Match the component with its purpose in the osmosis investigation:

  Potato/carrot/egg ↔️ Acts as the semi-permeable membrane

  Distilled water ↔️ Represents the high water concentration solution

  Sucrose/salt solution ↔️ Represents the low water concentration solution

  Ruler/balance ↔️ Measures changes in mass or length
• The potato/carrot/egg in the osmosis experiment acts as a semi-permeable membrane.


  True
• The sucrose/salt solutions in the osmosis experiment are prepared at varying concentrations
• What tools are used to measure changes in mass or length in the osmosis experiment?

  Balance and ruler
• Osmosis occurs from regions of higher to lower water concentration


  True
• Preparing solutions with varying solute concentrations creates a gradient
• Improvements to the osmosis experiment

  1️⃣ Use a more standardized membrane

  2️⃣ Control environmental conditions

  3️⃣ Increase the number of trials

  4️⃣ Automate measurements
• Osmosis is driven by the concentration gradient until equilibrium is reached.


  True
• What two tools can be used to measure changes in the osmosis experiment?

  Ruler and balance
• What material is used as the semi-permeable membrane in the osmosis experiment?

  Potato/carrot/egg
• Osmosis occurs until equilibrium is reached in the osmosis experiment

  True
• What does a positive change in mass indicate in the osmosis experiment?

  Water uptake
• What is a strength of using potato/carrot/egg as a semi-permeable membrane?

  Allows observation of osmosis
• What environmental factor is difficult to control in the osmosis experiment?

  Temperature
• Osmosis is the net movement of water molecules from an area of high water concentration to an area of low water concentration across a semi-permeable membrane
• Steps to set up the osmosis experiment:

  1️⃣ Cut potato/carrot/egg into similarly sized pieces

  2️⃣ Prepare sucrose/salt solutions of varying concentrations

  3️⃣ Place each piece in different beakers filled with different concentrations

  4️⃣ Leave overnight to observe osmosis

  5️⃣ Measure changes in mass or length
• Preparing sucrose/salt solutions of varying concentrations creates different concentration gradients.
• Steps to set up the osmosis experiment

  1️⃣ Cut potato/carrot/egg into pieces

  2️⃣ Prepare sucrose/salt solutions of varying concentrations

  3️⃣ Place pieces in separate beakers with solutions

  4️⃣ Leave overnight to allow osmosis

  5️⃣ Measure changes in mass or length
• Data from the osmosis experiment is organized in a table
• Match the safety precaution with its benefit:

  Wear safety goggles ↔️ Protects eyes from splashes

  Use plastic gloves ↔️ Protects skin from chemicals

  Clean work surfaces ↔️ Prevents contamination
• Potential variability in membrane permeability is a limitation of the osmosis experiment


  True
• To reduce human error, the measurement process can be automated