Ads
related to: is calcium carbonate corrosive in water or chlorine dioxide is considered
Search results
Results From The WOW.Com Content Network
Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid , but excessive consumption can be hazardous and cause hypercalcemia and digestive issues.
Calcium deposits, primarily composed of calcium carbonate (CaCO 3), react with weak acids to form calcium salts that are soluble in water. The general reaction can be represented as follows: CaCO 3 + 2H + → Ca 2+ + CO 2 + H 2 O. Here, H + represents the hydrogen ions provided by the acid
Carbonatation induced rebar corrosion. 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.
When atmospheric carbon dioxide (CO 2), or carbonate ions (HCO − 3, CO 2− 3 dissolved in water) diffuse into concrete from its external surface, they react with calcium hydroxide (portlandite, Ca(OH) 2) and the pH of the concrete pore water progressively decreases from 13.5 – 12.5 to 8.5 (pH of water in equilibrium with calcite).
However, there is an equilibrium between dissolved calcium bicarbonate and dissolved calcium carbonate as represented by the chemical equation Ca 2+ + 2 HCO − 3 ⇌ Ca 2+ + CO 2− 3 + CO 2 + H 2 O. Note that CO 2 is dissolved in the water. Carbon dioxide dissolved in water (aq) tends to equilibrate with carbon dioxide in the gaseous state (g ...
Rain water contains dissolved carbon dioxide taken from the atmosphere. Some of the dissolved carbon dioxide reacts with the water to form carbonic acid, which remains in solution. Minerals containing calcium and magnesium form soluble bicarbonates when exposed to carbonic acid. Water containing these minerals is known as "hard water".
3 – meaning the concentration of carbonate expressed as if calcium carbonate were the sole source of carbonate ions. An aqueous solution containing 120 mg NaHCO 3 (baking soda) per litre of water will contain 1.4285 mmol/l of bicarbonate, since the molar mass of baking soda is 84.007 g/mol. This is equivalent in carbonate hardness to a ...
The lime industry is a significant carbon dioxide emitter. The manufacture of one tonne of calcium oxide involves decomposing calcium carbonate, with the formation of 785 kg of CO 2 in some applications, such as when used as mortar; this CO 2 is later re-absorbed as the mortar goes off.