Question

Pour about 40–50 mL of bromothymol blue solution into each of the two jars. The solution should be blue at this point.
2. Make the solution acidic (turn it yellow) by bubbling CO2 into each jar: place a clean straw in the solution and blow gently for 5–15 seconds until the BTB turns yellow. (Do this the same for both jars so they start at the same color.)
3. Immediately place the Elodea sprig into Jar A (the experimental jar). Leave Jar B without a plant as the control.
4. Cover both jars with their lids (or cover cups) and place both jars in the same location with bright light (a sunny windowsill or under a lamp) so they get equal light and temperature.
5. Observe and record the color of the BTB in each jar at regular intervals (for example, at 10, 20, 30, 60 minutes, then hourly up to 3–4 hours). Also note any bubbles forming on the plant.
6. Continue observations for several hours. Optionally repeat the experiment with a duplicate set (replicate) or place a jar in the dark as an additional control.


shorten pls

Answer 1

1. Pour 40–50 mL bromothymol blue (BTB) into two jars — solution should be blue.
2. Make both acidic (turn yellow) by blowing CO2 through a clean straw for 5–15 s.
3. Put an Elodea sprig in Jar A (experimental); leave Jar B as the control.
4. Cover both jars and place them together in bright light.
5. Observe and record BTB color and any bubbles at intervals (e.g., 10, 20, 30, 60 min, then hourly up to 3–4 h).
6. Optionally repeat as a replicate or include a dark control.