Search results
Results from the WOW.Com Content Network
One type of amphoteric species are amphiprotic molecules, which can either donate or accept a proton (H +). This is what "amphoteric" means in Brønsted–Lowry acid–base theory . For example, amino acids and proteins are amphiprotic molecules because of their amine ( −NH 2 ) and carboxylic acid ( −COOH ) groups.
The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V 2 O 5) has since been preferred.
A proton is a subatomic particle in the nucleus with a unit positive electrical charge. It is represented by the symbol H + because it has the nucleus of a hydrogen atom, [2] that is, a hydrogen cation. A cation can be a conjugate acid, and an anion can be a conjugate base, depending on which substance is involved and which acid–base theory ...
Although nearly 100% sulfuric acid solutions can be made, the subsequent loss of SO 3 at the boiling point brings the concentration to 98.3% acid. The 98.3% grade, which is more stable in storage, is the usual form of what is described as "concentrated sulfuric acid".
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base.It can be used to determine pH via titration.Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.
For oxyacids with more than one ionizable hydrogen on the same atom, the pK a values often increase by about 5 units for each proton removed, [29] [30] as in the example of phosphoric acid above. It can be seen in the table above that the second proton is removed from a negatively charged species.
The "number of basic sites per unit surface area of the solid" is used to express how much basic strength is found on a solid base catalyst. [15] Scientists have developed two methods to measure the amount of basic sites: one, titration with benzoic acid using indicators and gaseous acid adsorption. [15]
Unit downtime to prepare for a full unit turnaround can take longer for HF units, since the reactor-settler system and all the fractionators must be neutralized before maintenance work can proceed. In H 2 SO 4 units, only the reactor-settler system requires neutralization. In addition, extensive safety equipment (breathing apparatus, etc.) is ...