Phenolphthalein Indicator AR 500ml

Phenolphthalein Indicator AR 500ml

A 500ml bottle of Analytical Reagent (AR) phenolphthalein is primarily a high-purity laboratory pH indicator.
It turns colourless in acidic environments and vibrant pink in alkaline solutions (pH \(8.2\) to \(10.0\)).

Introduction – What Is Phenolphthalein?
Phenolphthalein CAS 77-09-8 is a classic acid-base indicator and pH indicator widely used in both laboratory and industrial analyses. Its molecular formula is C20H14O4, and its structure comprises aromatic rings linked to a lactone (phthalide) framework. In acidic solutions, phenolphthalein exists in a colorless form; in basic media, it shifts to pink or fuchsia, providing a clear visual cue for endpoint detection in titrations and other analytical procedures.

Industrial applications
Chemical manufacturing and process control: Phenolphthalein serves as a pH-monitoring tool to adjust neutralization steps, maintain reactor conditions, and verify post-treatment acidity/alkalinity. Its clear color transition supports timely interventions in production lines.​

Water treatment and environmental testing: Used to assess alkalinity and to monitor neutralization in discharge streams, helping facilities meet regulatory standards and optimize chemical usage for environmental compliance.​

Pharmaceutical and quality control: In manufacturing settings, phenolphthalein is employed to verify pH specifications of formulations, inerting processes, and raw materials before downstream processing. It supports consistent product quality and traceability in QA/QC workflows.​

Primary uses include:
Acid-Base Titrations: Acts as a precise endpoint indicator for neutralisation reactions (especially strong acid/strong base titrations).
Alkalinity Testing: Used to monitor effluent discharge streams, water treatment, and ensure environmental compliance.
Forensics: Serves as a key reagent in presumptive tests (the Kastle-Meyer test) to detect the presence of blood.
Industrial Monitoring: Utilized in soap making and concrete carbonation testing to verify pH shifts

Phenolphthalein Indicator AR 500ml used in laboratory for research and analysis