What would you have expected to happen if the files were instead place in a dark room at the beginning of the experiment explain your answer? (Solution with chara turned turned green so it's neutral )(btb solution turned yellow so it was acidic ) Background and Procedure:The chemical bromothymol blue is an indicator that appears blue in an alkaline (base) medium and yellow-green in an acid medium. CO2 has been added to the bromothymol blue. Carbon dioxide (CO2) in solution formscarbonic acid (H2CO3), turning the bromothymol yellow-green.If carbon dioxide is removed from the solution, the solution will change to dark green and then to blue.Bromothymol blue will stain your hands and clothing. Practice safe laboratory procedures when performing thisactivity.1. With a permanent marker, write your initials (or group symbol) on both of the capped vials.2. Obtain an 8-cm sprig of Chara and place it in one of the vials provided.3. Over a paper towel, fill both vials to overflowing with the yellow-green bromothymol blue solution and captightly. Take care not to spill on your hands and thoroughly clean up any spills.4. Place both vials in sunlight or strong light source.5. Wait one hour, and then answer the questions for Activity 1.

An acid is a substance that can enhance the concentration of hydrogen ions (H+) in the aqueous solution. When the acid dissociation is maximum, it is termed as the strong acid. Similarly, the strong base undergoes complete dissociation to yield hydroxide ions (OH-) in the aqueous solution. The detection of the acidic or basic solution can be accomplished by adding suitable chemical substances to the respective solutions. The substance is termed as the indicator. Example: Phenolphthalein. The indicator provides the characteristic colors in the acidic and basic solutions. Analysis at the beginning of experiment: Photosynthesis is a biological process that involves the conversion of carbon dioxide and water into glucose and oxygen. This process is prevalent in plants and is catalyzed by sunlight and green pigments. On exposing to the sunlight, Sprig of Chara uptakes the carbon dioxide and the reduction of the carbon dioxide in the solution furnishes the blue solution of BTB indicator. When the sprig of Chara is prevented to direct exposure to the sunlight by keeping it in the darkroom, the liberation of the carbon dioxide to the solution will be greater. It is a kind of respiration process. The increase in the concentration of carbon dioxide in the solution enhances the acidity of the solution by increasing the concentration of carbonic acid (lower pH values). CO2(g)+H2O(l)→H2CO3(aq) So the addition of BPT indicator to the dark solution of the spring of Chara leads to the appearance of yellow-green due to its acidic nature.