How can sodium be broken down

Pure sodium has a light, silvery sheen and, like silver, has a very high reflectivity for light. However, this optical property cannot be used in normal everyday use: the very reactive alkali metal immediately turns gray in moist air. It is a very soft metal, the Mohs hardness is 0.5. It can be easily cut with the knife. Only potassium, cesium and rubidium are even softer.


Lithium, sodium and potassium
 


In the open air, elemental sodium binds oxygen, water and carbon dioxide and gradually converts to a mixture of sodium hydroxide, sodium carbonate and sodium hydrogen carbonate. Therefore it is kept under paraffin oil or petroleum as a protective liquid. After lithium and potassium, it is the element with the lowest density. In complete darkness, chemiluminescence occurs in the form of a green glow. Sodium has a low melting point and has good electrical conductivity and good thermal conductivity. The alkali metal is very reactive and burns in the air with a yellow flame. This produces yellow colored sodium peroxide Na2O2 and colorless sodium oxide Na2O. How much of each of the two oxides is produced during combustion depends on the moisture present, the oxygen content and the combustion temperature. At higher combustion temperatures, sodium peroxide is more likely to form.
 
4 Na + O2  2 Well2O     ΔHR. = −418 kJ / mol
2 Na + O2  N / A2O2    ΔHR. = −513 kJ / mol


At high pressure, sodium can be dissolved in pure oxygen to form the orange-colored sodium hyperoxide NaO2 oxidize. When ozone is passed over the strongly cooled hyperoxide, red sodium ozone NaO is obtained3which can be separated by extracting with liquid ammonia. The ozonide decomposes again at room temperature. [Lit 5]


Flame test with salts of alkali metals
 


 
 
 
Salts of sodium such as sodium chloride or sodium carbonate also produce a yellow flame color. Elemental sodium reacts violently with water to form hydrogen and sodium hydroxide. This dissolves immediately in the excess water to form caustic soda.
  
2 Na + 2 H2O 2 NaOH + H2       ΔHR. = −285.6 kJ / mol
  
The previously well debarked, pea-sized piece of sodium is initially deformed into a ball with a hiss, which then flies over the surface of the water. If the water is mixed with phenolphthalein solution before the experiment, the indicator turns the water pink due to the alkaline solution that forms.
 
 
Sodium reacts with water
 

 
If you add phenolphthalein solution to water and then add a small piece of sodium, this forms into a ball and whizzes around on the surface of the water while hissing. The phenolphthalein turns pink with the alkaline solution that forms.


If the resulting heat of reaction cannot be dissipated, for example when using very little water by placing a filter paper underneath or wrapping it in a cloth, the sodium ignites or even explodes. Burning sodium shows a strong, yellow flame.


Sodium burns on a damp filter paper
 

 
A piece of sodium on a filter paper will ignite when placed on water.


Sodium reacts explosively with fluorine. It burns violently in liquid bromine or when bromine vapors are passed over it. An explosion can also occur when using liquid bromine. In chlorine gas, sodium burns with a yellow flame to sodium chloride:
  
2 Na + Cl2  2 NaCl      ΔHR. = −514 kJ / mol
 
 
Sodium reacts with chlorine
 

 
A piece of sodium is heated in a test tube with a hole and held in a cylinder,
which is filled with chlorine. The sodium burns off and a white product is obtained.
 
  
Sodium also reacts with other substances. With hydrochloric acid, sodium chloride is formed with evolution of hydrogen; with sulfuric acid, hydrogen and sodium sulfate are formed. With alcohols you get alcoholates. The alkali metal can be safely disposed of by dissolving sodium in ethanol:
  
2 Na + 2 C2H5OH 2 C2H5ONa + H2