1. What is the function of cotton wool soaked in the experiment of light is needed for photosynthesis?
2. Is there any differences between using potassium hydroxide pellet or cotton wool soaked?
1. A cotton wool soaked in potassium hydroxide is needed for the absorbance of carbon dioxide. In the absence of carbon dioxide only first part of the photosynthesis will occur: water hydrolysis and oxygen production. Maybe this is the purpose of your experiment. 2. Carbon dioxide interacting with water gives weak acid that react with potassium hydroxide. The product is potassium bicarbonate. This is how potassium hydroxide absorbs carbon dioxide. That is why use better cotton wool soaked in the potassium hydroxide solution that will absorb carbon dioxide more effective than potassium hydroxide pellet.