{"id":85207,"date":"2025-06-01T03:07:49","date_gmt":"2025-06-01T03:07:49","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85207"},"modified":"2025-06-01T03:07:49","modified_gmt":"2025-06-01T03:07:49","slug":"calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/","title":{"rendered":"Calcium oxide reacts vigorously with water to produce slaked lime whos"},"content":{"rendered":"

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) ?<\/p>\n

[amp_mcq option1=”A \u2013 O\u2082 ; B \u2013 CaCO\u2083” option2=”A \u2013 CO\u2082 ; B \u2013 Ca(OH)\u2082” option3=”A \u2013 O\u2082 ; B \u2013 Ca(OH)\u2082” option4=”A \u2013 CO\u2082 ; B \u2013 CaCO\u2083” correct=”option4″]<\/p>\n

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UPSC CDS-1 – 2021<\/div>\n<\/div>\n
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\nCalcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083).
\n<\/section>\n
\nThe initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). This layer of calcium carbonate gives the walls a smooth, shiny finish after a few days as the reaction completes and the water evaporates.
\n<\/section>\n
\nThis process is a form of carbonation. The calcium carbonate layer is chemically similar to limestone and marble, providing a durable and aesthetically pleasing surface. This reaction also helps to ‘set’ the white-wash onto the wall surface.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

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) ? [amp_mcq option1=”A \u2013 O\u2082 ; B \u2013 CaCO\u2083” … <\/p>\n

Detailed SolutionCalcium oxide reacts vigorously with water to produce slaked lime whos<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1087],"tags":[1110,1202,1096],"class_list":["post-85207","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-1","tag-1110","tag-acid-base-and-salt","tag-chemistry","no-featured-image-padding"],"yoast_head":"\nCalcium oxide reacts vigorously with water to produce slaked lime whos<\/title>\n<meta name=\"description\" content=\"Calcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083). The initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). This layer of calcium carbonate gives the walls a smooth, shiny finish after a few days as the reaction completes and the water evaporates.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Calcium oxide reacts vigorously with water to produce slaked lime whos\" \/>\n<meta property=\"og:description\" content=\"Calcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083). The initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). This layer of calcium carbonate gives the walls a smooth, shiny finish after a few days as the reaction completes and the water evaporates.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:07:49+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Calcium oxide reacts vigorously with water to produce slaked lime whos","description":"Calcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083). The initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). This layer of calcium carbonate gives the walls a smooth, shiny finish after a few days as the reaction completes and the water evaporates.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/","og_locale":"en_US","og_type":"article","og_title":"Calcium oxide reacts vigorously with water to produce slaked lime whos","og_description":"Calcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083). The initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). This layer of calcium carbonate gives the walls a smooth, shiny finish after a few days as the reaction completes and the water evaporates.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T03:07:49+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/","url":"https:\/\/exam.pscnotes.com\/mcq\/calcium-oxide-reacts-vigorously-with-water-to-produce-slaked-lime-whos\/","name":"Calcium oxide reacts vigorously with water to produce slaked lime whos","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T03:07:49+00:00","dateModified":"2025-06-01T03:07:49+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"Calcium oxide (quicklime, CaO) reacts with water to form calcium hydroxide (slaked lime, Ca(OH)\u2082). When slaked lime solution is applied to walls during white-washing, it slowly reacts with carbon dioxide gas present in the air to form a thin, hard layer of calcium carbonate (CaCO\u2083). The initial reaction is CaO(s) + H\u2082O(l) \u2192 Ca(OH)\u2082(aq). This slaked lime solution is used for white-washing. The slaked lime then reacts with atmospheric carbon dioxide: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l). Component (A) from the air is carbon dioxide (CO\u2082), and the component (B) formed as a thin layer on the wall is calcium carbonate (CaCO\u2083). 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