Methyl Orange

Methyl Orange



From: £60.96

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Do you need Methyl Orange?

  • We supply methyl orange in 2.5L containers, with bulk discounts available
  • We also offer further options with all our products, from bespoke blending or personalised labelling
  • Simply contact us for more information or free technical advice

What is methyl orange?

Methyl orange is a popular pH indicator commonly used in titrations. With a clear colour change at a mid-point in the acidity scale, it’s a good option for acid titrations. With a pH below 3.1, the solution is red, but it gradually goes to orange and then a strong yellow when pH rises above 4.4. The reverse occurs when the pH is becoming more acidic.

Chemical and physical properties of methyl orange

  • Alternative names: Gold orange, acid orange and helianthin
  • IUPAC name: Sodium 4-[(4-dimethylamino)phenyldiazenyl]benzenesulfonate
  • Molecular formula: C14H14N3NaO3S
  • Molecular weight: 327.33 g/mol
  • Appearance: Orange/yellow powder
  • Melting point: Over 300 degree Celsius
  • Boiling point: Never reaches boiling point, but decomposes instead
  • Solubility: soluble in water and slightly soluble in pyrimidine, but insoluble in diethyl ether and alcohol
  • pH: Red at pH 3.1 and yellow at pH 4.4
  • Common uses: pH indicator and dye in the textile industry

Safety precautions

  • Has been shown to be mutagenic in animals, so safety procedures must be adopted in the lab when handling this chemical
  • In contrast, there is no evidence for an environmental or aquatic negative impact. This compound is typically quickly decomposed anaerobically, limiting the risk of bioaccumulation

Over 30 years’ experience

ReAgent has been established as a chemical manufacturer for over 30 years. During this period, we’ve built an enviable reputation for high quality products and excellent customer service. If you need help, a member of our customer service team will be glad to assist you before, during and after your purchase to ensure our products meet your needs.


MSDS Files

The following files are available to download:

Product ID Product post_status Bulk Download SDS File

Please note: we only deliver to registered UK businesses at non-residential addresses with a minimum order value of £100 before VAT

We only supply to mainland UK, contact us on 0800 990 3258 for rates to Ireland.

Please notify us if you have specific delivery requirements such as restricted access, requirement for a tail-lift delivery vehicle or pallet truck. Failure to notify us of a special delivery instructions can incur additional charges from our carriers.

Looking for further options on this product?

  • Custom packaging
  • Personalised labelling
  • Specific pack sizes
  • Different grades available
  • Bespoke blending
  • Bulk quantities

Call 0800 990 3258 for details or Contact Us

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