CO2 Uptake: measured by placing leaf in enclosed space w/ water → baking soda (bicarbonate) acts as source of carbon dioxide for plant, CO2 interacts w/ water, more hydrogen ions pulled from water, pH will increase → increased uptake will lower [] in solution and increase alkalinity; be aware of respiration, which can be done finding difference b/t CO2 produced in dark and in the light (in the light, photosynthesis and respiration both occur, but in the dark, only respiration occurs)