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Hydrogen peroxide is a chemical compound with the formula H 2 O 2. In its pure form, it is a very pale blue [ 5 ] liquid that is slightly more viscous than water . It is used as an oxidizer , bleaching agent, and antiseptic , usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concentrations for industrial use.
2, and the hydroperoxyl radical exist in equilibrium in aqueous solution: • O − 2 + H 2 O ⇌ HO • 2 + HO −. The pK a of HO 2 is 4.88. Therefore, about 0.3% of any superoxide present in the cytosol of a typical cell is in the protonated form. [4] It oxidizes nitric oxide to nitrogen dioxide: [2] • NO + HO • 2 → • NO 2 + HO •
Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun 's mass is oxygen. [ 19 ] Oxygen constitutes 49.2% of the Earth's crust by mass [ 69 ] as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust .
The number density (symbol: n or ρ N) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric number density, two-dimensional areal number density, or one-dimensional linear number density.
The atmospheric pressure is roughly equal to the sum of partial pressures of constituent gases – oxygen, nitrogen, argon, water vapor, carbon dioxide, etc.. In a mixture of gases, each constituent gas has a partial pressure which is the notional pressure of that constituent gas as if it alone occupied the entire volume of the original mixture at the same temperature. [1]
Its bulk properties partly result from the interaction of its component atoms, oxygen and hydrogen, with atoms of nearby water molecules. Hydrogen atoms are covalently bonded to oxygen in a water molecule but also have an additional attraction (about 23.3 kJ·mol −1 per hydrogen atom) to an adjacent oxygen atom in a separate molecule. [2]
Different hydrocarbon fuels have different contents of carbon, hydrogen and other elements, thus their stoichiometry varies. Oxygen makes up only 20.95% of the volume of air, and only 23.20% of its mass. [13] The air-fuel ratios listed below are much higher than the equivalent oxygen-fuel ratios, due to the high proportion of inert gasses in ...
Vapour density is the density of a vapour in relation to that of hydrogen. It may be defined as mass of a certain volume of a substance divided by mass of same volume of hydrogen. vapour density = mass of n molecules of gas / mass of n molecules of hydrogen gas . vapour density = molar mass of gas / molar mass of H 2