Caesium bromide
Cesium Bromide, a white crystalline chemical, is known as the CsBr. It's hygroscopic. Soluble in water, soluble in ethanol, almost insoluble in acetone. Relative density 4.44. Melting point is 636 ℃. The boiling point of 1300 ℃. The median lethal dose (rats, peritoneal cavity) was 1400mg/kg. Stimulating. It can be used as analytical reagent, X-ray screen, prism of spectrometer, etc.
Physical property data
1. Density (g/mL 25 ℃) : 4.44.
2. Melting point (℃) : 636.
3. Boiling point (℃, atmospheric pressure) : 1300.
4. Refractive index (N20 /D) : 1.6984.
5. Flash point (℃,) : 1300.
6. Solubility (mg/mL) : H2O: 3M AT20 °C.
Computational chemical data
1. Reference value for hydrophobic parameters calculation (XlogP) : None
2. Number of hydrogen bond donors: 0
3. Number of hydrogen bond receptors: 1
4. Number of rotatable bonds: 0
5. Number of tautomorphs: None
6. Topological molecular polarity surface area: 0
7. Number of heavy atoms: 2
8. Surface charge: 0
9. Complexity: 2
10. Number of isotope atoms: 0
11. Determine the number of atomic vertical centers: 0
12. Uncertain number of atomic vertical centers: 0
13. Determine the number of chemical bond vertical centers: 0
14. Uncertain number of chemical bond vertical centers: 0
15. Number of covalent bond units: 2
Properties and stability
If used and stored according to specifications, it will not decompose.
Avoid contact with water and moisture. Cesium bromide is stable in the air, melting above 600℃, the melt is not alkaline, sublimation above the melting point without decomposition, 900℃ is strong volatilization. It is soluble in water, with a solubility of 55.23g cesium bromide per 100g at 25℃ .
The synthetic methods
Mainly used hydrobromic acid to neutralize cesium carbonate; Cesium iodide was treated with hydrobromic acid in the presence of hydrogen peroxide and recrystallized in water.
The more common method is to mix 16.17g cesium sulfate and 14.36g barium bromide (slightly excessive), add water and heat them, Then evaporated the filtrate to dry, red hot residue will be treated with water, recrystallization. The resulting small grains were stored in sulfuric acid vacuum dryer.
Another method of making pure products is to dissolve the aluminum alum containing cesium in water, convert it with ammonia water into cesium sulfate, and filter out the aluminum while it is hot. Place the sulfate with a little excess barium hydroxide, pass the carbon dioxide to precipitate the excess barium, leave it overnight to precipitate the barium sulfate and barium carbonate completely. Filtrate containing cesium hydroxide was filtered into platinum dish and neutralized with hydrobromic acid. Recrystallization yields pure cesium bromide. The pure white cesium bromide was heated at 150℃ for 8h, dissolved in water, settled with pure concentrated hydrobromic acid, and filtered. Melt in nitrogen atmosphere or hydrogen bromide atmosphere, cool in pure nitrogen, stored in a dryer of potassium hydroxide.
The storage method
Store in a tight container in a cool, dry place.
Fire-fighting Precautions and Protective measures:
Fire fighters shall wear respirators and full - body fire suits to put out the fire upwind.
Remove the container from the fire as much as possible into an open area.
Evacuate immediately if containers in the fire are discolored or emit sound from the safety relief device.
Isolate the scene of the accident and keep out irrelevant personnel. Collect and treat fire water to prevent environmental pollution.
Leak emergency treatment
Operating personnel protective measures, protective equipment and emergency disposal procedures:
It is recommended that emergency responders wear respirators, antistatic clothing and rubber oil-resistant gloves.
Do not touch or cross the spill.
All equipment used in the operation shall be earthed.
Cut off the source as much as possible.
Eliminate all ignition sources.
The warning area shall be designated according to the area affected by liquid flow, steam or dust diffusion, and irrelevant personnel shall evacuate to the safety area from the crosswind or upwind.
Environmental protection measures:
Absorb leakage and avoid polluting the environment. Prevent leakage into sewers, surface water and groundwater.
Methods of receiving and removing the leaking chemicals and materials used for disposal:
Small leakage: Collect leaking liquids in airtight containers where possible. Absorb with sand, activated carbon or other inert materials and transfer to a safe place. Do not flush into drains.
Massive leakage: levee or pit. Seal the drainage pipe. Cover with foam to inhibit evaporation. Transfer to tank truck or special collector with explosion-proof pump to recover or transport to waste disposal site.