Methyl Orange CAS 547-58-0 Factory Supply in Bulk Package

• CAS No.: 547-58-0
• Formula: C14h14n3nao3s
• EINECS: 208-925-3
• Classification: Organic Analytical Reagents
• Grade: Ind
• Specific Usage: For Biological Purpose, For Microbiological, Technical Grade
• Model NO.: IND
• Content: Standard
• Usage: Laboratory Reagents, Analytical Reagents
• Source: Concrete
• Habit Appellation: Fine Chemicals
• Application: Scientific Research
• Property: Organic Reagent
• Appearance: Orange or Yellow Solid
• Density: 0.987 G/Ml at 25 °c
• Boiling Point: 100ºC
• Melting Point: 300 °c
• Flash Point: 37 °c
• Transport Package: 25 Kgs Fiber Drums
• Specification: IND
• Trademark: Sinochembt
• Origin: Shenyang

Product Description

• 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 pK_a 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.
• Item                                                      (Ind)
• Assay,%                                             ≥ 18.5~22.0
• pHVisnal transition interval                 3.0()~4.4()
• Sensitivity                                        
• Insoluble matter in water,%                  ≤0.15
• Oxide

• Indicator colors

  
  Methyl orange solutions

  In a solution that decreases in acidity, methyl orange moves from the color red to orange and finally to yellow with the opposite occurring for a solution increasing in acidity. This color change from yellow to red occurs because the protons in the acidic solution react with the N=N bond of the molecule, protonating one of them and changing the visible light absorption of the molecule to reflect more red light than orange/yellow.

  Methyl orange (pH indicator)
  below pH 3.1		above pH 4.4
  3.1	⇌	4.4

  In an acid, it is reddish and in alkali, it is yellow. Methyl orange has a pK_a of 3.47 in water at 25 °C (77 °F).^[4]

  Other indicators

  pH indicator

  Methyl orange in xylene cyanol solution (pH indicator)
  below pH 3.2		above pH 4.2
  3.2	⇌	4.2

  Modified (or screened) methyl orange, an indicator consisting of a solution of methyl orange and xylene cyanol, changes from grey-violet to green as the solution becomes more basic.

  Safety

  Methyl orange has mutagenic properties.When methyl orange is put under oxidative stress, one of the double-bonded nitrogen atoms that connects the aromatic rings gets radicalized and can further break down into reactive oxygen species or anilines, which are carcinogenic and can mutate DNA. Various bacteria and enzymes can also cause this breakdown to occur.

  Synthesis

  Methyl Orange is an azobenzene derivative that can be formed from dimethylaniline  through first, a diazonium salt formation with the s ulfanilic acid, followed by a nucleophilic attack from the dimethylaniline and rearomatization.