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Its solubility product K sp of 5.02 × 10 −6 at 25 °C, [1] its dissociation in water is large enough that its solutions are basic according to the following dissolution reaction: Ca(OH) 2 → Ca 2+ + 2 OH −. The solubility is affected by the common-ion effect. Its solubility drastically decreases upon addition of hydroxide or calcium sources.
In chemistry, a strong electrolyte is a solute that completely, or almost completely, ionizes or dissociates in a solution. These ions are good conductors of electric current in the solution. Originally, a "strong electrolyte" was defined as a chemical compound that, when in aqueous solution, is a good conductor of electricity. With a greater ...
The hydrate phase, [3 CaO · 2 SiO 2 · 3 H 2 O], is referred to as the "C-S-H" phase. It grows as a mass of interlocking needles that provide the strength of the hydrated cement system. Relatively high belite reactivity is desirable in Portland cement manufacture, and the formation of the unreactive γ-form must be rigorously avoided.
By rewriting the last reaction in the inverse direction one obtains a reaction consistent with what is observed in the lime sulfur global reaction: 3 / 8 S 8 + 2 H 2 O → 2 H 2 S + SO 2. In alkaline conditions, it gives: 3 / 8 S 8 + 2 H 2 O + 6 OH − → 2 S 2− + SO 2− 3 + 5 H 2 O. and after simplification, or more exactly recycling, of ...
The tetrahydrate crystallizes as a solid solution of Ca 3 (SO 3)2(SO 4). 12H 2 O and Ca 3 (SO 3)2(SO 3). 12H 2 O. The mixed sulfite-sulfate represents an intermediate in the oxidation of the sulfite to the sulfate, as is practiced in the production of gypsum. This solid solution consists of [Ca 3 (SO 3) 2 (H 2 O) 12] 2+ cations and either ...
Cement hydration and strength development mainly depend on two silicate phases: tricalcium silicate (C 3 S) , and dicalcium silicate (C 2 S) . [1] Upon hydration, the main reaction products are calcium silicate hydrates (C-S-H) and calcium hydroxide Ca(OH) 2, written as CH in the cement chemist notation. C-S-H is the phase playing the role of ...
Calcium hydrosulfide is the chemical compound with the formula Ca(HS) 2 or CaH 2 S 2. [1] It is formed from the reaction of calcium hydroxide or calcium carbonate with hydrogen sulfide: [2] Ca(OH) 2 + 2H 2 S → Ca(HS) 2 + 2H 2 O CaCO 3 + 2H 2 S → Ca(HS) 2 +H 2 O+CO 2
Carbonatation is a slow process that occurs in concrete where lime (CaO, or Ca(OH) 2 ) in the cement reacts with carbon dioxide (CO 2) from the air and forms calcium carbonate. The water in the pores of Portland cement concrete is normally alkaline with a pH in the range of 12.5 to 13.5.