Hydrogen is a chemical element with the symbol H and the atomic number 1. Hydrogen is the lightest element. Hydrogen is a gas made of diatomic molecules with the formula H2 under normal conditions. It has no odour, no colour, is non-toxic, and is very combustible. Hydrogen is the most prevalent chemical element in the universe, making up roughly 75% of all ordinary matter. In its plasma state, the Sun, for example, is primarily made up of hydrogen. The vast majority of hydrogen on the earth is present in molecular forms such as water and organic compounds.
Let’s discuss the chemical properties of H2O2 examples and their meaning in detail.
Origin: Hydrogen peroxide is the most basic member of the peroxide family, having been discovered as a chemical compound in 1818 by French chemist J.L. Thenard. Its chemical formula is H2O2. In the environment, hydrogen peroxide is found in extremely small concentrations. Gaseous hydrogen peroxide is produced by photochemical processes in the earth’s atmosphere. It serves as both a disinfectant and a bleaching agent. At 298 degrees Fahrenheit, it’s acidic, with a pH of 6 to 7.
Structure of Hydrogen Peroxide
- Peroxide, a chemical molecule, contains the peroxide ion (O2–2). It is formed by a single bond between two oxygen atoms. It’s a very strong oxidant.
- Hydrogen peroxide is a non-planar molecule formed by 2 oxygen atoms joined together by a single covalent bond called the peroxide bond.
- It’s formatted like a book. Each oxygen atom has a single connection connecting it to a hydrogen atom. The two bonds do not lie in the same plane because lone pairs of electrons repel each other over oxygen atoms.
- When hydrogen peroxide is gaseous, the dihedral angle between the two planes is 111.5o, but 90.2o when it is crystalline. Intramolecular hydrogen bonding causes this. This is caused by intramolecular hydrogen bonding.
Chemical Properties
Talking about the chemical properties of H2O2 UPSC notes, it is a one-of-a-kind material due to its molecular structure. It is made up of oxygen atoms in the oxidation state -1, as opposed to the oxidation states 0 or -2 found in many other compounds. This means that, depending on the pH of its solution, this chemical can operate as an oxidizer or a reducer.
- Decomposition: Some of the chemical properties of H2O2 examples include:
- Light-induced decomposition: H2O2 is also decomposed by exposure to light. As a result, it’s stored in wax-lined glass or plastic containers with urea as a stabiliser.
- Auto-oxidation and auto-reduction: Hydrogen peroxide is a highly unstable liquid in its purest state. It decomposes into water and oxygen when left out for a long time or heated.
The breakdown process is accelerated by the presence of metals such as platinum, gold, metal oxides (MnO2), or particular metal ions such as Fe2+ ions. Even a rough surface helps it break down.
Acidic Nature: It is one of the important chemical properties of H2O2 due to the following reasons:
- It turns blue litmus red, H2O2 is a weak acid. The aqueous solution does not affect the litmus. Its dissociation constant (1.55×10–12 at 293 K) is slightly higher than H2O’s (1.0×10–14), H2O2 is just marginally stronger than H2O.
- Hydrogen peroxide’s acidic nature is demonstrated by its neutralising interactions with hydroxides and carbonates. For example: (OH)2+H2O2→BaO2+2H2O.
- H2O generates hydroperoxides (acidic salts) and peroxides (peroxides) since it contains two ionizable H–atoms (normal salts).
Physical Properties of Hydrogen Peroxide
- Hydrogen peroxide is a faint blue tint in its anhydrous state. It’s an odourless, viscous, syrupy liquid due to H-bonding.
- It has a harsh flavour that creates blisters on the skin.
- It is soluble in water, alcohol, and ether.
- Hydrogen peroxide is viscous and denser than water (1.44g/cm3) because H2O2 molecules have stronger H-bonds than H2O molecules, this occurs.
- Its boiling point is 150 degrees Celsius, while its freezing point is 0.89 degrees Celsius. Because hydrogen peroxide’s intermolecular hydrogen bonding is stronger than that of water, its boiling point increases even higher.
- The dipole moment of hydrogen peroxide (2.1D) is somewhat higher than that of water (1.84D).
- Hydrogen peroxide is diamagnetic and has both polar and non-polar bonds.
Conclusion
Hydrogen peroxide is a chemical molecule that is extremely unstable. Hydrogen Peroxide is formed when two hydrogen molecules react with two oxygen molecules. As a result, the chemical formula is H2O2. In its fundamental form, hydrogen peroxide is a pale blue, colourless liquid that is somewhat more viscous than water.
It is the most basic type of peroxide (since it is a compound with an oxygen-oxygen single bond). It’s found in a variety of biological systems, including the human body. The enzymes that consume or break down hydrogen peroxide are known as peroxidases.
