Search results
Results from the WOW.Com Content Network
Calcium bromide is the name for compounds with the chemical formula Ca Br 2 (H 2 O) x. Individual compounds include the anhydrous material (x = 0), the hexahydrate (x = 6), and the rare dihydrate (x = 2). All are white powders that dissolve in water, and from these solutions crystallizes the hexahydrate.
In chemistry, the ECW model is a semi-quantitative model that describes and predicts the strength of Lewis acid–Lewis base interactions. Many chemical reactions can be described as acid–base reactions, so models for such interactions are of potentially broad interest. The model initially assigned E and C parameters to
The E and C parameters refer, respectively, to the electrostatic and covalent contributions to the strength of the bonds that the acid and base will form. The equation is -ΔH = E A E B + C A C B + W. The W term represents a constant energy contribution for acid–base reaction such as the cleavage of a dimeric acid or base.
Calcium bromate, Ca(BrO 3) 2, is a calcium salt of bromic acid. It is most commonly encountered as the monohydrate, Ca(BrO 3) 2 •H 2 O. [citation needed] It can be prepared by reacting calcium hydroxide with sodium bromate or calcium sulfate with barium bromate. Above 180 °C, calcium bromate decomposes to form calcium bromide and oxygen.
The standard Gibbs free energy of formation (G f °) of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).
Alphabet Energy was a startup company founded in 2009 at the University of California, Berkeley by thermoelectrics expert Matthew L. Scullin [2] and Peidong Yang. [3] The company uses nanotechnology and materials science applications to create thermoelectric generators that are more cost effective than previous bismuth telluride -based devices.
A third example is illustrated by the chemical reaction of dissociation of a weak acid HA (such as acetic acid, A = CH 3 COO −): HA ⇌ H + + A −. Vinegar contains acetic acid. When acid molecules dissociate, the concentration of the undissociated acid molecules (HA) decreases and the concentrations of the product ions (H + and A −) increase.
A Lewis base is also a Brønsted–Lowry base, but a Lewis acid does not need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases ( HSAB theory ) followed in 1963. The strength of Lewis acid-base interactions, as measured by the standard enthalpy of formation of an adduct can be predicted by the Drago–Wayland ...