The sodium peroxide is a chemical compound of the formula Na 2 O 2 having two ionic bonds between the two sodium atoms and the O2 molecule. It exists in various hydrates and peroxyhydrates including Na 2 O 2 · 2H 2 O 2 · 4H 2 O, Na 2 O 2 · 2H 2 O, Na 2 O 2 · 2H 2 O 2, and Na 2 O 2 · 8H 2 O.
It has a hexagonal crystalline structure, however, when heated this form undergoes a transition to a phase of unknown symmetry at 512 ° C. Its crystalline structure is presented in figure 2 (Sodium: sodium peroxide, 1993-2016).
Figure 1: Structure of sodium peroxide.
Figure 2: Crystal structure of sodium peroxide.
Sodium peroxide can be prepared on a large scale by reacting metallic sodium with oxygen at 130-200 ° C (Ashford, 1994), a process that generates sodium oxide, which in a separate stage absorbs oxygen:
4 Na + O 2 → Na 2 O
2 Na 2 O + O 2 → 2 Na 2 O 2
The present batch process involves the oxidation of sodium in sodium monoxide with dry air and subsequent oxidation of the monoxide in peroxide with 90% oxygen.
In 1951, USI began operating the first continuous process for the production of sodium peroxide. The process is unique in one respect: it uses air instead of pure oxygen.
Variations of a batch process have been used for almost 70 years (SCHOW, 1957), for example, the commercial product contains between 90 and 95% hydrogen peroxide.
Physical and chemical properties of sodium peroxide
Sodium peroxide is a compound classified as a strong base, explosive and strong oxidizing agent according to its reactivity alert. Mixtures with combustible material are easily ignited by friction, heat or contact with moisture.
It can decompose vigorously under prolonged exposure to heat, causing the containers containing it to break.
Very dangerous in case of contact with skin and eyes (irritant) and in cases of ingestion and inhalation. Prolonged exposure can cause skin burns and ulcerations. Inhalation overexposure may cause respiratory irritation.
Inflammation of the eye is characterized by redness, watering, and itching. Inflammation of the skin is characterized by itching, peeling, redness, or occasionally blistering.
In case of eye contact, you should check if you are wearing contact lenses and remove them. Eyes should be flushed immediately with running water for at least 15 minutes, keeping the eyelids open.
In case of skin contact, the contaminated skin is gently and carefully washed with running water and non-abrasive soap. Cold water can be used. Irritated skin should be covered with an emollient.
If the contact with the skin is severe, it should be washed with a disinfectant soap and cover the contaminated skin with an antibacterial cream.
In case of inhalation, the victim should be allowed to rest in a well-ventilated area.
Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a shirt collar, belt, or tie. If breathing is difficult, give oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation.
If swallowed, do not induce vomiting. If the victim is not breathing, perform mouth-to-mouth resuscitation.
In all cases, immediate medical attention should be sought (Material Safety Data Sheet Sodium peroxide, 2013).
Applications
Sodium peroxide is used in clothing bleaches as it reacts with water to produce hydrogen peroxide, a bleaching agent according to the reaction:
Na 2 O 2 + 2 H 2 O → 2 NaOH + H 2 O 2
In addition to hydrogen peroxide, the reaction produces sodium hydroxide (lye), which keeps the solution alkaline. Hot water and an alkaline solution are both necessary for hydrogen peroxide to work best as a bleach (Field, SF).
Sodium peroxide is used to bleach wood pulp for the production of paper and textiles. It is currently used primarily for specialized laboratory operations, for example mineral extraction. In addition, sodium peroxide is used as an oxidizing agent in chemical reactions.
It is also used as a source of oxygen by reacting it with carbon dioxide to produce oxygen and sodium carbonate, therefore, it is particularly useful in diving equipment, submarines, etc. (Using sodium peroxide to scrub carbon dioxide emissions, 2014).
References
- Ashford, R. (1994). Ashford's Dictionary of Industrial Chemicals. London: Publications Ltd.
- Field, S. (SF). Ingredients –Sodium peroxide. Retrieved from sci-toys.com.
- Material Safety Data Sheet Sodium peroxide. (2013, May 21). Retrieved from sciencelab.com.
- National Center for Biotechnology Information. (SF). PubChem Compound Database; CID = 14803. Retrieved from PubChem.
- Royal Society of Chemistry. (2015). Sodium peroxide. Retrieved from chemspider.com.
- SCHOW, HR (1957). The Sodium Peroxide Production Story. Advances in Chemistry, Vol. 19, 118-123.
- SODIUM PEROXIDE. (2016). Retrieved from cameochemicals.
- Sodium: sodium peroxide. (1993-2016). Retrieved from webelements.
- Using sodium peroxide to scrub carbon dioxide emissions. (2014, November 10). Retrieved from stackexchange.