GROWTH DEVELOPMENT CHILD
SUMMATIVE ASSESSMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Ca(OH)2(aq)+CaOCa(OH)2+H2
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CaO+H2Ca(OH)2
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Ca(OH)2(aq) + H2Ca(OH)2(aq)
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None of the above
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Detailed explanation-1: -The formation of slaked lime (calcium hydroxide, Ca(OH)2) when water is added to lime (CaO) is exothermic. CaO(s) + H2O (l) → Ca(OH)2(s) This reaction occurs when water is added to dry portland cement to make concrete, and heat evolution of energy as heat is evident because the mixture becomes warm.
Detailed explanation-2: -The balanced chemical equation is as follows: Ca + 2 H 2 O → Ca ( OH ) 2 + H 2 Calcium Water Calcium hydroxide Hydrogen.
Detailed explanation-3: -The exothermic reaction with water yields enough energy to evaporate the water. Ca(OH)2 is only slightly soluble in water (0.16g Ca(OH)2/100g water at 20°C) forming a basic solution called lime water.
Detailed explanation-4: -The balanced eqn is : Ca+2H2O→Ca(OH)2+H2.