Ad
related to: can h2 exist in water
Search results
Results From The WOW.Com Content Network
The triple point is at a temperature of 273.16 K (0.01 °C; 32.02 °F) and a pressure of 611.657 pascals (0.00604 atm; 0.0887 psi); [71] it is the lowest pressure at which liquid water can exist. Until 2019, the triple point was used to define the Kelvin temperature scale. [72] [73]
Liquid and solid phases can exist in combination at the triple point, a substance known as slush hydrogen. [39] Metallic hydrogen, a phase obtained at extremely high pressures (in excess of 400 gigapascals (3,900,000 atm; 58,000,000 psi)), is an electrical conductor. It is believed to exist deep within giant planets like Jupiter. [38] [40]
Water is a tasteless, odorless liquid at ambient temperature and pressure. Liquid water has weak absorption bands at wavelengths of around 750 nm which cause it to appear to have a blue color. [4] This can easily be observed in a water-filled bath or wash-basin whose lining is white. Large ice crystals, as in glaciers, also appear blue.
For example, a water molecule contains two hydrogen atoms, but does not contain atomic hydrogen (which would refer to isolated hydrogen atoms). Atomic spectroscopy shows that there is a discrete infinite set of states in which a hydrogen (or any) atom can exist, contrary to the predictions of classical physics .
Modelling suggests that enough natural hydrogen exists to meet humanity's demand for hydrogen for thousands of years, however most of this cannot be extracted economically. [ 5 ] [ 6 ] Natural hydrogen has been identified in many source rocks in areas beyond the sedimentary basins where oil companies typically operate.
Since water is often considered harmless to the environment, an engine burning it can be considered "zero emissions". In aviation, however, water vapor emitted in the atmosphere contributes to global warming (to a lesser extent than CO 2). [11] Liquid hydrogen also has a much higher specific energy than gasoline, natural gas, or diesel. [12]
Concentrated solar power can achieve the high temperatures necessary to split water. Hydrosol-2 is a 100-kilowatt pilot plant at the Plataforma Solar de Almería in Spain which uses sunlight to obtain the required 800 to 1,200 °C (1,070 to 1,470 K; 1,470 to 2,190 °F) to split water. Hydrosol II has been in operation since 2008.
Water molecules have two hydrogen atoms and one oxygen atom. While H 2 is not very reactive under standard conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. [1]