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प्रश्न
Write the method of preparation of Ca(OH)2. What happens when CO2 is passed through it? Write balanced chemical equation for the reaction involved.
उत्तर
- The method of preparation of calcium hydroxide Ca(OH)2 involves adding water to calcium oxide (quick lime). When water is slowly added to calcium oxide, it reacts vigorously to produce slaked lime (calcium hydroxide), releasing a significant amount of heat in the process. The chemical equation for this reaction is:
\[\ce{CaO(s) + H2O(l) -> Ca(OH)2(aq) + Heat}\] - When carbon dioxide CO2 is passed through a solution of calcium hydroxide, it reacts to form calcium carbonate CaCO3 and water. This reaction is depicted by the equation:
\[\ce{Ca(OH)2(aq) + CO2(g)->CaCO3(s) + H2O(l)}\] - If an excess of carbon dioxide is passed through the mixture, it further reacts with the calcium carbonate to form calcium bicarbonate, which is soluble in water:
\[\ce{CaCO3(s) + H2O(l) + CO2(g) -> Ca(HCO3)2(aq)}\] - This sequence of reactions begins with a combination reaction to form calcium hydroxide, followed by a double displacement reaction upon the introduction of carbon dioxide, first leading to the precipitation of calcium carbonate and then, upon the introduction of more carbon dioxide, forming the soluble calcium bicarbonate. The compound that precipitates in the initial reaction with CO2 is calcium carbonate CaCO3 , and the ions present in it are Ca2+ and `"CO"_3^(2-).`
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संबंधित प्रश्न
Give an example of a double displacement reaction other than the one given in the following Activity.
•Take about 3 mL of sodium sulphate
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• In another test tube, take about 3 mL of
barium chloride solution.
• Mix the two solutions given in the following fig.
• What do you observe?
A metal X forms a water soluble salt XNO3. When an aqueous solution of XNO3 is added to common salt solution, then a white precipitate of compound Y is formed alongwith sodium nitrate solution. Metal X is said to be the best conductor of electricity and it does not evolve hydrogen when put in dilute hydrohloric acid.
(a) What is metal X?
(b) What is salt XNO3?
(c) Name the compound Y.
(d) Write the chemical equation of the reaction which takes place on reacting XNO3 solution and common salt solution giving the physical states of all the reactants and products.
(e) What type of chemical reaction is illustrated by the above equation?
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Choose and write the correct option.
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Choose the correct option from given alternative:
In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution:
(A) exchange of atoms takes place
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(C) a precipitate is produced
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