Indicator
| Formula / Notation | Visual pH/endpoint indicator; e.g., phenolphthalein: colourless (acid) → pink (base) |
|---|---|
| Also Known As | pH indicator, titration indicator, visual indicator, acid-base indicator |
What is Indicator?
A substance that changes color depending on the pH of a solution, used to signal the end point in acid-base titrations. Common indicators include litmus (red in acid, blue in base), phenolphthalein (colorless in acid, pink in base), and universal indicator.
Formula & Notation
Other Names / Synonyms: pH indicator, titration indicator, visual indicator, acid-base indicator
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
A substance that changes color depending on the pH of a solution, used to signal the end point in acid-base titrations. Common indicators include litmus (red in acid, blue in base), phenolphthalein (colorless in acid, pink in base), and universal indicator.
Indicators are used in: acid-base titrations (phenolphthalein, methyl orange, universal indicator), redox titrations (ferroin, starch for iodine), complexometric titrations (Eriochrome Black T for EDTA), as pH test strips (universal indicator on paper), and in qualitative tests (litmus for acid/base…
Some indicators are toxic or mutagenic (crystal violet, acridine orange, ethidium bromide used as DNA stains in gel electrophoresis). Methanol-based indicator solutions are flammable and toxic. Always check SDS for specific indicators. Phenolphthalein is a mild laxative but considered a possible car…
The formula or notation for Indicator is: Visual pH/endpoint indicator; e.g., phenolphthalein: colourless (acid) → pink (base)