Methyl Orange Chemical Properties

Melting point:

300 °C

Density 

0.987 g/mL at 25 °C

Flash point:

37 °C

storage temp. 

Store at +5°C to +30°C.

solubility 

5g/l

form 

Powder/Solid

pka

3.4(at 25℃)

Colour Index 

13025

color 

Yellow-Orange

Specific Gravity

0.987

Odor

Odorless

PH

6.5 (5g/l, H2O, 20℃)

PH Range

3.1(Red)-4.4(Orange)

Water Solubility 

Soluble in ethanol. Partially soluble in hot water. Slightly soluble in cold water and pyrimidine. Insoluble in ether and alcohol.

λmax

507nm, 522nm, 464nm

Merck 

14,6105

BRN 

4732884

Stability:

Stable. Incompatible with strong oxidizing agents.

Biological Applications

Detecting microorganisms; treating dermatological diseases,vaginal affections; dental materials; wound dressing materials

Major Application

Liquid crystals, thin films, sensors, sol-gel matrix, waveguides, host-guest chemistry, display device, corrosion inhibitor, glass coatings, paints, wound dressing materials, pharmaceuticals, dental materials, measuring nucleic acid

CAS DataBase Reference

547-58-0

EPA Substance Registry System

Methyl orange (547-58-0)

Safety Information

Hazard Codes 

T

Risk Statements 

25-10

Safety Statements 

45-24/25-16-36/37/39

RIDADR 

UN 3143 6.1/PG 3

WGK Germany 

3

RTECS 

DB6327000

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

III

HS Code 

29270000

Hazardous Substances Data

547-58-0(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: 60 mg/kg

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Methyl Orange Usage And Synthesis

Description

Methyl orange is an orange, azoic dye. It has a transition range from 3.1 to 4.4. Methyl orange does not have a full spectrum of color change, but has a sharper end point. Methyl orange shows red color in acidic medium (pH < 3.1) and yellow color in basic medium (pH > 4.4). It is used as a pH-indicator in 0.1% aqueous solution for the titration of mineral acids (not organic acids) and strong bases. Methyl orange is also used in dyeing and printing textiles as a dyestuff.

References

[1] https://en.wikipedia.org/wiki/Methyl_orange
[2] Mohammed Bassim Alqaragully (2014) International Journal of Advanced Research in Chemical Science, 1, 48-59

Chemical Properties

Orange-yellow powder. Soluble in hotwater; insoluble in alcohol.

Uses

Methyl orange is a pH indicator frequently used in titrations, also used for histological microscopy.

Uses

As indicator in 0.1% aqueous solution. pH: 3.1 red, 4.4 yellow. Employed for titrating most mineral acids, strong bases, estimating alkalinity of waters; useless for organic acids. In dyeing and printing of textiles.

Definition

An acid–base indicator that is red in solutions below a pH of 3 and yellow above a pH of 4.4. As the transition range is clearly on the acid side, methyl orange is suitable for the titration of an acid with a moderately weak base, such as sodium carbonate.

Definition

methyl orange: An organic dyeused as an acid–base indicator. Itchanges from red below pH 3.1 toyellow above pH 4.4 (at 25°C) and isused for titrations involving weakbases.

Preparation

4-Aminobenzenesulfonic acid diazo, and N,N-dimethylaniline coupling.

General Description

Orange powder.

Air & Water Reactions

Azo dyes can be explosive when suspended in air at specific concentrations. Insoluble in water.

Reactivity Profile

Methyl Orange is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.

Purification Methods

Recrystallise it twice from hot water, then wash it with a little EtOH followed by diethyl ether. It is an indicator: pH 3.1 (red) and pH 4.4 (yellow). [Beilstein 16 IV 510.]

Properties and Applications

orange. The strong sulfuric acid for green light yellow, diluted into red orange. The dye solution to join strong hydrochloric acid for orange red; Add thick sodium hydroxide solution for green light yellow.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO
AATCC

Methyl Orange(547-58-0)Related Product Information

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