Hydrogen Peroxide and its different uses

Hydrogen peroxide

Hydrogen peroxide is a chemical compound with an H₂O₂ formula. In its pure form, it is a very pale blue liquid, somewhat more viscous than water. It is a simple peroxide. It contains a compound with an oxygen-oxygen single bond. It is used as an oxidizer, bleaching agent, and antiseptic. Concentrated hydrogen peroxide, or high-test peroxide, is a reactive oxygen species and has been used as a propeller in rocketry. Its chemistry is dominated by the nature of its volatile peroxide bonds.

Hydrogen peroxide is volatile and decomposes slowly in the presence of light. Due to its volatility, hydrogen peroxide is usually stored in a dark-colored bottle with a stabilizer in a weakly acidic solution. This peroxide is found in biological systems, including the human body.

Characteristics

The boiling point of H₂O₂ is about 50 °C higher than water at 150.2 °C. In practice, when hydrogen peroxide is heated to this temperature, the potential explosive heat will pass through decomposition. It can be safely distilled at low temperatures under reduced pressure.

Decomposition of H₂O₂

Hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen with a ΔH of -2884.5 kJ/kg and a ΔS of 70.5 J/ (mol·K):

2 H₂O₂ → 2 H₂O + O₂

The rate of decomposition increases with a rise in temperature, concentration, and pH, with cool, dilute, and acidic solutions showing the best stability.

Chemical Reaction

a. In acidic solutions, H₂O₂ is a powerful oxidizer, stronger than chlorine, chlorine dioxide, and potassium permanganate.

In acidic solutions Fe²⁺ is oxidized to Fe³⁺:

 2 Fe²⁺ (aq) + H₂O₂ + 2 H⁺ (aq) → 2 Fe³⁺ (aq) + 2 H₂O (l)

 And sulfite (SO₃²⁻) is oxidized to sulfate (SO₄²⁻).

b. In a basic solution, hydrogen peroxide can reduce a variety of inorganic ions. For example, hydrogen peroxide will reduce sodium hypochlorite and potassium permanganate is a convenient method for preparing oxygen in the laboratory:

NaOCl + H₂O₂ → O₂ + NaCl + H₂O

2 KMnO₄ + 3 H₂O₂ → 2 MnO₂ + 2 KOH + 2 H₂O + 3 O₂

Uses

a. About 60% of the world's production of hydrogen peroxide is used for pulp- and paper-bleaching.

b. The second major industrial application is the production of sodium percarbonate and sodium perborate, which are used as mild bleach in laundry detergents.

c. Hydrogen peroxide is used in certain waste-water treatment processes to remove organic impurities.

d. It may be used for the sterilization of various surfaces, including surgical tools, and may be deployed as a vapor (VHP) for room sterilization.

e. It may be used to treat acne, although benzoyl peroxide is a more common treatment.

f. It has various domestic uses, primarily as a cleaning and disinfecting agent.

g. Diluted H₂O₂ (between 1.9% and 12%) mixed with aqueous ammonia has been used to bleach human hair.

h. It can be used either as a monopropellant (not mixed with fuel) or as the oxidizer component of a bipropellant rocket. Hydrogen peroxide at a concentration of 70-98% between steam and oxygen used as a monopropellant takes advantage of the decomposition.

i. Hydrogen peroxide is used in aquaculture for controlling mortality caused by various microbes.