Investigating the Molar Concentration of Citric Acid in Different Commercial Candies via Acid-Base Titration with Sodium Hydroxide

This investigation explores how the molar concentration of citric acid varies among different commercial candy brands. The study employs volumetric acid-base titration using 0.100 mol dm⁻³ sodium hydroxide and phenolphthalein as an indicator to determine titratable acidity.

Results indicate significant differences: Pikotas exhibited the highest concentration (17.1%), followed by Respiral (13.2%) and Piruleta (8.3%), correlating with sensory acidity perceptions. The analysis is strengthened by rigorous stoichiometric calculations based on a 1:3 molar ratio and comprehensive uncertainty propagation.

The paper provides a high-quality evaluation of experimental errors, distinguishing between random errors in titration readings and systematic errors related to indicator endpoint and reagent stability.