Hydrogen Carbonate, single set of standard solutions. (pH7.6 - 9.2 in increments of 0.2 pH units)

These coloured solutions are used in conjunction with algal ball photosynthesis experiments.

In these experiments, Hydrogen Carbonate indicator, SI20, changes colour in response to the concentration of dissolved carbon dioxide, which is determined by the balance of photosynthesis (which consumes CO₂) and respiration (which produces CO₂).

Set Includes: 9 vials (7mL each) containing boric acid/ borax buffer and Hydrogen Carbonate indicator.

Color range from yellow (pH 7.6) to purple (pH 9.2)

How to use:

• You can visually match the colour of the algal ball photosynthesis vials to the colour of the standard pH solutions in order to estimate the pH of the photosynthesis vials.
• You can use a colorimeter (green filter) or a spectrophotometer (550nm) to prepare a calibration line of absorbance versus pH.
• You can then measure the absorbance of your algal ball photosynthesis vials and read off their pH value from the calibration line.