Practical 10.5 Measurement of the rate of transpiration using a bubble potometer

Experimental Setup for Bubble Potometer
🌱 Submerge the bubble potometer in water to ensure it is completely filled, eliminating any trapped air bubbles.
✂️ Cut a leafy shoot from a plant and secure it tightly into the potometer while underwater to ensure an airtight seal.
💧 Apply vaseline to all junctions to prevent any potential leaks that could disrupt experimental accuracy.
🧻 Gently dry the shoot with tissue paper and allow a 5-minute equilibration period before beginning measurements.

Measurement Procedure and Data Collection
🫧 Introduce a single air bubble into the capillary tube by briefly lifting the end out of the water and re-submerging it.
⏱️ Record the initial and final positions of the bubble over a set time interval, such as 15 minutes.
🔄 Utilize the reservoir tap to return the bubble to the starting position, allowing for repeat measurements to ensure consistency.
📊 Calculate the total distance traveled by the bubble to determine the rate of transpiration in the plant specimen.

Key Points & Insights
➡️ Consistency is critical: Always perform at least three readings and calculate the average to minimize experimental error and variability.
➡️ System maintenance: Ensure the capillary tube is clean and free of residue to allow for smooth bubble movement during the observation period.
➡️ Environmental control: Keep the leafy shoot dry after initial setup to ensure that transpiration rates reflect natural water loss through the leaves.

📸 Video summarized with SummaryTube.com on Apr 09, 2026, 02:53 UTC