Search results
Results from the WOW.Com Content Network
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.
CaO + H 2 O → Ca(OH) 2 Ca(OH) 2 + CO 2 → CaCO 3 + H 2 O. In a laboratory, calcium carbonate can easily be crystallized from calcium chloride (CaCl 2), by placing an aqueous solution of CaCl 2 in a desiccator alongside ammonium carbonate [NH 4] 2 CO 3. [10] In the desiccator, ammonium carbonate is exposed to air and decomposes into ammonia ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Calcium hydroxide is modestly soluble in water, as seen for many dihydroxides. Its solubility increases from 0.66 g/L at 100 °C to 1.89 g/L at 0 °C. [8] 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:
Burning (calcination) of calcium carbonate in a lime kiln above 900 °C (1,650 °F) [4] converts it into the highly caustic material burnt lime, unslaked lime or quicklime (calcium oxide) and, through subsequent addition of water, into the less caustic (but still strongly alkaline) slaked lime or hydrated lime (calcium hydroxide, Ca(OH) 2), the ...
Calcium chlorate – Ca(ClO 3) 2; Calcium chloride – CaCl 2; Calcium chromate – CaCrO 4; Calcium cyanamide – CaCN 2; Calcium fluoride – CaF 2; Calcium hydride – CaH 2; Calcium hydroxide – Ca(OH) 2; Calcium monosilicide – CaSi; Calcium oxalate – CaC 2 O 4; Calcium hydroxychloride – CaOCl 2; Calcium perchlorate – Ca(ClO 4) 2 ...
Don't rely on bloviating pundits to tell you who'll prevail on Hollywood's big night. The Huffington Post crunched the stats on every Oscar nominee of the past 30 years to produce a scientific metric for predicting the winners at the 2013 Academy Awards.
Increasing atmospheric concentration of CO 2 from combustion of fossil fuels are causing the CCD to rise, with zones of downwelling first being affected. [8] Ocean acidification , which is also caused by increasing carbon dioxide concentrations in the atmosphere, will increase such dissolution and shallow the carbonate compensation depth on ...