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methyl orange

Structure via PubChem · Public domain (PubChem)

EntityQ409196· pop 42· linked from 38 articles

methyl orange

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pH indicator

OverviewAI-generated

Methyl orange is a chemical compound with the formula C₁₄H₁₄N₃NaO₃S. Its IUPAC name is sodium 4-[[4-(dimethylamino)phenyl]diazenyl]benzenesulfonate. The substance has a mass of 327.065357 and a weight of 327.34. It possesses a density of 1.28 and a melting point of 300. The compound is associated with the sRGB color hex triplet E32600.

Chemical properties include a topological polar surface area of 93.5. It has zero hydrogen bond donors and six hydrogen bond acceptors. The overall charge is 0. The canonical SMILES representation is CN(C)C1=CC=C(C=C1)N=NC2=CC=C(C=C2)S(=O)(=O)[O-].[Na+].

Methyl orange is referenced by 38 other encyclopedia articles. A search for the term yields 4374 results in PubMed literature.

Synthesized by Vinony from 19 facts across 4 sources: Wikidata, PubMed, PubChem, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.

Chemical data

Formula
C14H14N3NaO3S
Molecular weight
327.34 g/mol
IUPAC name
sodium 4-[[4-(dimethylamino)phenyl]diazenyl]benzenesulfonate
SMILES
CN(C)C1=CC=C(C=C1)N=NC2=CC=C(C=C2)S(=O)(=O)[O-].[Na+]
InChIKey
STZCRXQWRGQSJD-UHFFFAOYSA-M
Polar surface area
93.5 Ų
H-bond donors
0
H-bond acceptors
6
Formal charge
0

via PubChem

Research

4,374 papers

via PubMed

~3 min read

Encyclopedic overview

Methyl orange is a pH indicator frequently used in titration because of its clear and distinct color variance at different pH values. Methyl orange shows red color in acidic medium and yellow color in basic medium. Because it changes color at the pKa of a mid strength acid, it is usually used in titration of strong acids in weak bases that reach the equivalence point at a pH of 3.1-4.4. Unlike a universal indicator, methyl orange does not have a full spectrum of color change, but it has a sharp end point. In a solution becoming less acidic, methyl orange changes from red to orange and, finally, to yellow—with the reverse process occurring in a solution of increasing acidity.

Indicator colors

Excerpted from Wikipedia’s “methyl orange” article, available under the CC BY-SA 4.0 licence.