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Pozzolanic reaction is a long term reaction, which involves dissolved silicic acid, water and CaO or Ca(OH) 2 or other pozzolans to form a strong cementation matrix. This process is often irreversible. Sufficient amount of free calcium ion and a high pH of 12 and above is needed to initiate and maintain the pozzolanic reaction. [2]
Hydrogen phosphate or monohydrogen phosphate (systematic name) is the inorganic ion with the formula [HPO 4] 2-. Its formula can also be written as [PO 3 (OH)] 2-. Together with dihydrogen phosphate, hydrogenphosphate occurs widely in natural systems. Their salts are used in fertilizers and in cooking. [1]
Dicalcium phosphate is the calcium phosphate with the formula CaHPO 4 and its dihydrate. The "di" prefix in the common name arises because the formation of the HPO 4 2– anion involves the removal of two protons from phosphoric acid, H 3 PO 4.
The general formula of a phosphoric acid is H n+2−2x P n O 3n+1−x, where n is the number of phosphorus atoms and x is the number of fundamental cycles in the molecule's structure, between 0 and n + 2 / 2 . Pyrophosphate anion. Trimethyl orthophosphate.
Phosphorus comprises 0.1% by mass of the average rock [12] (while, for perspective, its typical concentration in vegetation is 0.03% to 0.2%), [13] and consequently there are quadrillions of tons of phosphorus in Earth's 3×10 19-ton crust, [14] albeit at predominantly lower concentration than the deposits counted as reserves, which are ...
This is done by adding H 2 O, OH −, e −, and/or H + to either side of the reaction until both atoms and charges are balanced. Consider the half reaction below: OH −, H 2 O, and e − can be used to balance the charges and atoms in basic conditions, as long as it is assumed that the reaction is in water.
P 4 + 4 OH − + 4 H 2 O → 4 H 2 PO − 2 + 2 H 2. Any phosphites produced in this step can be selectively precipitated out by treatment with calcium salts. The purified material is then treated with a strong, non-oxidizing acid (often sulfuric acid) to give the free hypophosphorous acid: H 2 PO − 2 + H + → H 3 PO 2. HPA is usually ...
Solid HP(O)(OH) 2 has tetrahedral geometry about the central phosphorus atom, with a P−H bond of 132 pm, one P=O double bond of 148 pm and two longer P−OH single bonds of 154 pm. In common with other phosphorus oxides with P−H bonds (e.g. hypophosphorous acid and dialkyl phosphites ), [ 2 ] it exists in equilibrium with an extremely minor ...