Search results
Results From The WOW.Com Content Network
into exo and endo ring closures, depending whether the bond broken during the ring closure is inside (endo) or outside (exo) the ring that is being formed; into tet, trig and dig geometry of the atom being attacked, depending on whether this electrophilic carbon is tetrahedral (sp 3 hybridised), trigonal (sp 2 hybridised) or diagonal (sp ...
Sublimation is caused by the absorption of heat which provides enough energy for some molecules to overcome the attractive forces of their neighbors and escape into the vapor phase. Since the process requires additional energy, sublimation is an endothermic change.
The opposite of an endothermic process is an exothermic process, one that releases or "gives out" energy, usually in the form of heat and sometimes as electrical energy. [1] Thus, endo in endothermic refers to energy or heat going in, and exo in exothermic refers to energy or heat going out. In each term (endothermic and exothermic) the prefix ...
Photosynthesis, the process that allows plants to convert carbon dioxide and water to sugar and oxygen, is an endothermic process: plants absorb radiant energy from the sun and use it in an endothermic, otherwise non-spontaneous process. The chemical energy stored can be freed by the inverse (spontaneous) process: combustion of sugar, which ...
In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid.
Water vapour from humid winter-air deposits directly into a solid, crystalline frost pattern on a window, without ever being liquid in the process.. Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase.
The prefix endo is reserved for the isomer with the substituent located closest, or "syn", to the longest bridge. The prefix exo is reserved for the isomer with the substituent located farthest, or "anti", to the longest bridge. Here "longest" and "shortest" refer to the number of atoms that comprise the bridge.
Endo and exo transition states for cyclopentadiene adding to acrolein; endo/exo product ratio for this and various other dienophiles. Diels–Alder reactions in which adjacent stereocenters are generated at the two ends of the newly formed single bonds imply two different possible stereochemical outcomes.