The letters pH stand for power of hydrogen and used to measure how acidic and basic a solution is. This measurement is important in science education such as chemistry, biology, medicine, food and environmental science, oceanography, civil engineering and many other fields. According to Lumen Learning (n.d.), in the field of science education, pH or acid-base indicators are frequently employed in titrations in analytical and organic chemistry, even in biology to determine the extent of a chemical reaction.For this reason, different types of indicators are used to measure the pH of solutions. Most of the commonly used pH indicators are commercial indicators, which are made synthetically such as phenolphthalein, methyl red and methyl orange. Also, acid-base indicators like litmus papers and pH strips are considered to be synthetic. These commercial pH indicators are usually of high cost. Thus, leads to unavailability or limited quantity in the science laboratories (Alijandre and Ripalde, 2015). Aside from high cost, synthetic commercial pH indicators are said to be made up of compounds that are highly polluting, harmful and hazardous for the environment (Chemistry Stack Exchange, n.d).Since the world has become aware for environmental issues, various researches are being undertaken extensively by many scientists all over the world in this field for production of natural products that will serve as pH indicators in which it will be less hazardous, lower cost, easily available, and eco-friendly. Dalubhasaan ng Lunsod ng San Pablo, as a local college, sometimes lacks funding for equipment and supplies most especially in science laboratories due to resources like chemicals and indicators that are needed are too expensive and considerably not affordable.
Consignado et al. (Wed,) studied this question.