Calcium oxide reacts vigorously with water to produce slaked lime whose solution is used for white-washing walls. This slaked lime reacts with component (A) in air to form a thin layer of component (B) to give a shiny finish. What are the components (A) a

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Q: (CDS-I/2021)
Calcium oxide reacts vigorously with water to produce slaked lime whose solution is used for white-washing walls. This slaked lime reacts with component (A) in air to form a thin layer of component (B) to give a shiny finish. What are the components (A) and (B) ?

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,10,22,4,10,8,10

keywords: 

{'calcium oxide reacts': [0, 0, 0, 1], 'lime reacts': [0, 0, 0, 1], 'lime': [1, 0, 5, 12], 'shiny finish': [0, 0, 0, 1], 'cacog': [0, 0, 0, 1], 'components': [1, 1, 3, 6], 'component': [1, 1, 1, 7], 'washing walls': [0, 0, 0, 1], 'coa': [1, 0, 0, 1], 'solution': [2, 0, 7, 14], 'water': [65, 15, 80, 129], 'thin layer': [0, 0, 1, 2]}

Option 1: A-02; B-CaCOg - This option is incorrect. Oxygen (O2) is not the component that reacts with slaked lime to form a thin layer for a shiny finish. Additionally, the chemical formula CaCOg does not exist.

Option 2: A-COa; B — Ca(OH)2 - This option is incorrect. Carbon dioxide (CO2) is not the component that reacts with slaked lime to form a thin layer for a shiny finish. The correct compound formed is calcium carbonate (CaCO3), not Ca(OH)2.

Option 3: A-02; B - Ca(OH)2 - This option is incorrect. Oxygen (O2) is not the component that reacts with slaked lime to form a thin layer for a shiny finish. The correct compound formed is calcium carbonate (CaCO3), not Ca(OH)2.

Option 4: A-COa; B-CaCOg - This is the correct answer. Component A is carbon dioxide (CO2), which reacts with slaked lime (Ca(OH)2) and forms a thin layer of component B, calcium carbonate (CaCO3). This reaction gives a shiny finish when used for