---
title: Thymolphthalein
date: 2025-03-05T12:13:46Z
modified: 2026-09-14T12:45:01Z
permalink: "https://allanchem.com/thymolphthalein/"
type: page
status: publish
excerpt: ""
wpid: 4534
timestamp: 2026-09-14T12:45:01Z
tags: []
---

##### CAS Number

125-20-2















##### Grade

NA















##### Packaging

Various







































Thymolphthalein is an organic compound historically used as a pH indicator. It is a weak acid-base indicator that changes color depending on the acidity (pH) of a solution.
**Chemical Formula:** : C₂₆H₃₀O₄
**Appearance:** A white to slightly yellowish crystalline powder
**Uses:**
**Pharmaceuticals:** In diagnostic tests and medical research, thymolphthalein can be incorporated into test kits or reagents as a pH indicator.
**Medicinal Research:** Used in medicinal research and pharmaceutical development.
**Acid-Base Indicator**: Thymolphthalein changes color from colorless in acidic solutions (pH below 8.0) to a bright blue in basic or alkaline solutions (pH above 10.0).
**Textile Dyeing and Finishing:** Thymolphthalein can be used in textile dyeing and finishing processes as a pH indicator or colorant.







































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