In this lab, our group performed an acid-base titration in order to determine an amount of substance found in an unknown sample. The acid used in this experiment is hydrochloric acid (HCl), due to its strength of acidity and its ability to dissolve completely in aqueous solutions. The base used in this experiment is sodium carbonate (Na2CO3) also known as “soda ash”. A similar compound is sodium bicarbonate (NaHCO3) which is commonly known as baking soda. When added to water, Na2CO3dissociates and carbonic acid and sodium hydroxide is produced3.Sodium carbonate has many uses in the real world, as it has many disinfectant properties. For example, it can be used to clean many surfaces in a household2. In order for our group to determine the amount of carbonate found in the sample, our group must first analyze how much Na2CO3 is used in the titration, and the volume of the standardized HCl solution that was used. There are two indicators used in this experiment: phenolphthalein and bromocresol green. Phenolphthalein turns the solution from colorless to dark pink. Bromocresol green changes the color of the solution from colorless to blue, then green once the primary endpoint is reached. If the primary endpoint passes, the color changes from green to yellow1. Procedure and MaterialsPart I: Standardization of the 0.12 M HCl solution:Acquire 0.12 M HCl from the lab administrator in a weighing bottle that has been provided.