Hydrogen peroxide (H2O2) is a chemical compound with the formula H2O2, which is used as an oxidizer, bleaching agent, and antiseptic. It is found in biological systems, including the human body, and is classified as peroxidases. H2O2 has a boiling point of 150.2 °C (302.4 °F), which is approximately 50 °C higher than water. It is a reactive oxygen species and the simplest peroxide, with an oxygen-oxygen single bond. It decomposes slowly into water and elemental oxygen when exposed to light and rapidly in the presence of organic or reactive compounds. Hydrogen peroxide is a nonplanar molecule with (twisted) C2 symmetry, with a relatively high rotational barrier of 386 cm−1 (4.62 kJ/mol) for rotation between enantiomers via the trans configuration and 2460 cm−1 (29.4 kJ/mol) via the cis configuration. This barrier is due to repulsion between the lone pairs of the adjacent oxygen atoms and dipolar effects between the two O–H bonds. The approximately 100° dihedral angle between the two O–H bonds makes the molecule chiral, and it is the smallest and simplest molecule to exhibit enantiomerism. The molecular structures of gaseous and crystalline H2O2 are significantly different due to the effects of hydrogen bonding, which is absent in the gaseous state. Crystals of H2O2 are tetragonal with the space group D4 or P41212. In aqueous solutions, hydrogen peroxide differs from the pure substance due to the effects of hydrogen bonding between water and hydrogen peroxide molecules. Hydrogen peroxide and water form an eutectic mixture, with freezing-point depression down as low as -56 °C. The boiling point of the same mixtures is also depressed in relation to the mean of both boiling points, occurring at 114 °C. Hydrogen peroxide has several structural analogues with HmX−XHn bonding arrangements, with the highest theoretical boiling point and melting point. The analogues all adopt similar skewed structures due to repulsion between adjacent lone pairs.
The CAS Number of Hydrogen Peroxide is 7722-84-1
The Molecular Formula of Hydrogen Peroxide is H2O2
The Molecular Mass of Hydrogen Peroxide is 34.01
The SMILES Notation of Hydrogen Peroxide is OO
The InChI Notation of Hydrogen Peroxide is InChI=1S/H2O2/c1-2/h1-2H