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The overall chemical reaction is: CO 2 + Ca(OH) 2 → CaCO 3 + H 2 O + heat (in the presence of water) Each mole of CO 2 (44 g) reacts with one mole of calcium hydroxide (74 g) and produces one mole of water (18 g). The reaction can be considered as a strong-base-catalysed, water-facilitated reaction. [5]
Heat: Quicklime releases thermal energy by the formation of the hydrate, calcium hydroxide, by the following equation: [11] CaO (s) + H 2 O (l) ⇌ Ca(OH) 2 (aq) (ΔH r = −63.7 kJ/mol of CaO) As it hydrates, an exothermic reaction results and the solid puffs up.
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.
Gas N 2 H 4: 95.4 Hydrazine: Liquid N 2 H 4: 50.6 Nitrous oxide: Gas N 2 O 82.05 Nitric oxide: Gas NO 90.29 Dinitrogen tetroxide: Gas N 2 O 4: 9.16 Dinitrogen pentoxide: Solid N 2 O 5: −43.1 Dinitrogen pentoxide: Gas N 2 O 5: 11.3 Nitric acid: Aqueous HNO 3: −207 Monatomic oxygen Gas O 249 Oxygen: Gas O 2: 0 Ozone: Gas O 3: 143 White ...
The standard Gibbs free energy of formation (G f °) of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).
Each ion can be either monatomic (termed simple ion), such as sodium (Na +) and chloride (Cl −) in sodium chloride, or polyatomic, such as ammonium (NH + 4) and carbonate (CO 2− 3) ions in ammonium carbonate. Salts containing basic ions hydroxide (OH −) or oxide (O 2−) are classified as bases, such as sodium hydroxide and potassium oxide.
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.
The reaction of calcium carbide with water, producing acetylene and calcium hydroxide, [5] was discovered by Friedrich Wöhler in 1862. CaC 2 + 2 H 2 O → C 2 H 2 + Ca(OH) 2 . This reaction was the basis of the industrial manufacture of acetylene, and is the major industrial use of calcium carbide.