An experiment to show that germinating seeds liberate carbon dioxide.

Set up

Air is drawn over the germinating seeds using a suction pump for some time.

Observation

Lime water in conical flask D turns milk while that in in flask B does not because carbon dioxide was removed by potassium hydroxide.

Conclusion

Carbon dioxide is produced by germinating seeds.

Alternatively

Set  up

The experiment is allowed to stand for some time

Observations

Water rises in the capillary tube because seeds use up oxygen during  respiration and carbon dioxide produced is absorbed by sodium hydroxide solution