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History of electrochemistry. Electrochemistry, a branch of chemistry, went through several changes during its evolution from early principles related to magnets in the early 16th and 17th centuries, to complex theories involving conductivity, electric charge and mathematical methods. The term electrochemistry was used to describe electrical ...
Degassing, also known as degasification, is the removal of dissolved gases from liquids, especially water or aqueous solutions. There are numerous methods for removing gases from liquids. Gases are removed for various reasons. Chemists remove gases from solvents when the compounds they are working on are possibly air- or oxygen-sensitive ( air ...
Mineral evolution. Most minerals on Earth formed after photosynthesis by cyanobacteria (pictured) began adding oxygen to the atmosphere. Mineral evolution is a recent hypothesis that provides historical context to mineralogy. It postulates that mineralogy on planets and moons becomes increasingly complex as a result of changes in the physical ...
In the original 1952 experiment, methane (CH 4), ammonia (NH 3), and hydrogen (H 2) were all sealed together in a 2:2:1 ratio (1 part H 2) inside a sterile 5-L glass flask connected to a 500-mL flask half-full of water (H 2 O). The gas chamber was intended to represent Earth's prebiotic atmosphere, while the water simulated an ocean. The water ...
Cavendish discovered hydrogen as a colorless, odourless gas that burns and can form an explosive mixture with air, and published a paper on the production of water by burning inflammable air (that is, hydrogen) in dephlogisticated air (now known to be oxygen), the latter a constituent of atmospheric air (phlogiston theory).
Oxygen gas can also be produced through electrolysis of water into molecular oxygen and hydrogen. DC electricity must be used: if AC is used, the gases in each limb consist of hydrogen and oxygen in the explosive ratio 2:1. A similar method is the electrocatalytic O 2 evolution from oxides and oxoacids.
For example, when sulfuric acid (H 2 SO 4) flows through steel pipes, the iron in the steel reacts with the acid to form a passivation coating of iron sulfate (FeSO 4) and hydrogen gas (H 2). The iron sulfate coating will protect the steel from further reaction; however, if hydrogen bubbles contact this coating, it will be removed.
Oxygen began building up in the atmosphere at approximately 1.85 Ga. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [ 4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 ...