Search results
Results from the WOW.Com Content Network
Oxyhydrogen is a mixture of hydrogen (H 2) and oxygen (O 2) gases. This gaseous mixture is used for torches to process refractory materials and was the first [1] gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing ...
In thermolysis, water molecules split into hydrogen and oxygen. For example, at 2,200 °C (2,470 K; 3,990 °F) about three percent of all H 2 O are dissociated into various combinations of hydrogen and oxygen atoms, mostly H, H 2, O, O 2, and OH. Other reaction products like H 2 O 2 or HO 2 remain minor. At the very high temperature of 3,000 ...
Combustion of hydrogen with the oxygen in the air. When the bottom cap is removed, allowing air to enter at the bottom, the hydrogen in the container rises out of top and burns as it mixes with the air. Space Shuttle Main Engine burning hydrogen with oxygen, produces a nearly invisible flame at full thrust. Hydrogen gas is highly flammable:
Demonstration model of a direct methanol fuel cell (black layered cube) in its enclosure Scheme of a proton-conducting fuel cell. A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) [1] into electricity through a pair of redox reactions. [2]
In the breakdown of a compound into its constituent parts, the generalized reaction for chemical decomposition is: AB → A + B (AB represents the reactant that begins the reaction, and A and B represent the products of the reaction) An example is the electrolysis of water to the gases hydrogen and oxygen: 2 H 2 O(l) → 2 H 2 (g) + O 2 (g)
Hence, a single reaction only offers one freedom degree (T) to produce hydrogen and oxygen only from heat (though using Le Chatelier's principle would also allow to slightly decrease the thermolysis temperature, work must be provided in this case for extracting the gas products from the system)
Hydrogen gas released in this way can be used as hydrogen fuel, but must be kept apart from the oxygen as the mixture would be extremely explosive. Separately pressurised into convenient 'tanks' or 'gas bottles', hydrogen can be used for oxyhydrogen welding and other applications, as the hydrogen / oxygen flame can reach approximately 2,800°C.
The fuel cell produces power through a redox reaction between hydrogen and oxygen. At the anode, hydrogen is oxidized according to the reaction: + + producing water and releasing electrons. The electrons flow through an external circuit and return to the cathode, reducing oxygen in the reaction: