Product Name: Bromocresol Green
Cas No.:76-60-8
Molecular formula:C21H14Br4O5S
Molecular weight: 698.01
Appearance: Light yellow or light gray powder
Product details:
Chemical properties: light yellow or light gray powder, insoluble in water, soluble in ethanol and diluted solution; The precipitates from acetic acid are fine yellow crystals. Slightly soluble in water, soluble in ethanol, ether, ethyl acetate and benzene. It is very sensitive to alkali and shows a special blue-green color in case of alkaline aqueous solution. The melting point is 225 ℃, the density is 0.79 g/mL at 20℃, and the flash point is 12℃.
Application: 1. Indicator: yellow when pH = 3.8, blue-green when pH = 5.4, and obvious color change when pH = 4.5. 2. Cell stain. 3. Used as acid-base indicator.
Quality standard:
Items | Standard |
PH discoloration domain | 3.8(Yellow green)----5.4(Blue) |
Maximum absorption wavelength(nm) λ1(PH 3.8) λ2 (PH 5.4) | 440~445 615~618 |
Mass absorption coefficient,L/cm·g α1(λ1PH 3.8,Dry sample) α2(λ2PH 5.4,Dry sample) | 24~28 53~58 |
Ethanol dissolution test | Qualified |
Burning residue(sulfate) | ≤0.25 |
Loss on drying | ≤3.0 |