Praktikum Sifat Koligatif Larutan (Tekanan Osmosis)

Scientific concepts / nature phenomena presented

• Osmotic pressure / osmosis (solvent transfer)

  • Water moves via a semipermeable membrane from a more dilute (hypotonic) solution to a more concentrated (hypertonic) solution.

• Hypotonic vs. hypertonic solutions

  • Plain water is treated as hypotonic relative to the potato/carrot cells (lower solute concentration outside).
  • Salt water is treated as hypertonic relative to the cells (higher solute concentration outside).

• Cell water movement and resulting changes

  • In salt water (hypertonic):
    • Water is drawn out of the cells
    • Cells shrink, becoming softer/less rigid (tissue texture can change depending on structure).
  • In plain water (hypotonic):
    • Water enters the cells
    • Cells swell, potentially maintaining or increasing hardness/size.

• Observed macroscopic outcomes (from the 30-minute soaking)

  • Carrots
    • Plain water: length increases (the text “about one billion” is likely a misread of units/amount).
    • Salt water: length decreases by about 3 milli (likely mm).
    • Texture:
      • Plain water: remains hard
      • Salt water: becomes soft and elastic
  • Potatoes
    • Plain water: length increases (the text “about one billion” is likely a misread of units/amount).
    • Salt water: length decreases by about 3 milli (likely mm).
    • Texture:
      • Plain water: remains hard
      • Salt water: becomes elastic and soft

Methodology / experiment outline (as described)

1. Prepare solutions

   • Add water to beakers (the text mentions “40 glasses containing water”).
   • Add salt to create salt water.
   • Stir until evenly mixed.

2. Prepare samples

   • Cut carrots and potatoes into pieces
   • Carrots are described as approximately ~5 cm.

3. Soak samples

   • Place carrot and potato pieces into:
     • Plain water
     • Salt water

4. Wait

   • Let samples stand for 30 minutes.

5. Measure / observe

   • Drain and record differences in:
     • Length (size change)
     • Texture (hard vs. soft/elastic)

Researchers / sources featured

• No specific researchers or external scientific sources are named in the subtitles.