{"id":92647,"date":"2025-06-01T11:29:49","date_gmt":"2025-06-01T11:29:49","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=92647"},"modified":"2025-06-01T11:29:49","modified_gmt":"2025-06-01T11:29:49","slug":"two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/","title":{"rendered":"Two reactants in a flask produce bubbles of gas that turn limewater mi"},"content":{"rendered":"

Two reactants in a flask produce bubbles of gas that turn limewater milky. The gas is<\/p>\n

[amp_mcq option1=”SO\u2082” option2=”NO\u2082” option3=”CO” option4=”CO\u2082” correct=”option4″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CISF-AC-EXE – 2019<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe gas that turns limewater milky is CO\u2082.
\n<\/section>\n
\nLimewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082).
\nWhen carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy.
\nThe chemical reaction is:
\nCa(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l)<\/p>\n

If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears.
\nCaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq)<\/p>\n

Other gases listed:
\n– SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082.
\n– NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn’t produce a milky precipitate with limewater as characteristically as CO\u2082.
\n– CO (Carbon monoxide) is a neutral gas and does not react with limewater.<\/p>\n

Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.
\n<\/section>\n

\nThis reaction is commonly used in experiments to detect the production of carbon dioxide, such as in respiration or combustion.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

Two reactants in a flask produce bubbles of gas that turn limewater milky. The gas is [amp_mcq option1=”SO\u2082” option2=”NO\u2082” option3=”CO” option4=”CO\u2082” correct=”option4″] This question was previously asked in UPSC CISF-AC-EXE – 2019 Download PDFAttempt Online The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is … <\/p>\n

Detailed SolutionTwo reactants in a flask produce bubbles of gas that turn limewater mi<\/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":[1089],"tags":[1119,1096,1239],"class_list":["post-92647","post","type-post","status-publish","format-standard","hentry","category-upsc-cisf-ac-exe","tag-1119","tag-chemistry","tag-inorganic-chemistry","no-featured-image-padding"],"yoast_head":"\nTwo reactants in a flask produce bubbles of gas that turn limewater mi<\/title>\n<meta name=\"description\" content=\"The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082). When carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy. The chemical reaction is: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l) If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears. CaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq) Other gases listed: - SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082. - NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn't produce a milky precipitate with limewater as characteristically as CO\u2082. - CO (Carbon monoxide) is a neutral gas and does not react with limewater. Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.\" \/>\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\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Two reactants in a flask produce bubbles of gas that turn limewater mi\" \/>\n<meta property=\"og:description\" content=\"The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082). When carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy. The chemical reaction is: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l) If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears. CaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq) Other gases listed: - SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082. - NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn't produce a milky precipitate with limewater as characteristically as CO\u2082. - CO (Carbon monoxide) is a neutral gas and does not react with limewater. Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T11:29:49+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":"Two reactants in a flask produce bubbles of gas that turn limewater mi","description":"The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082). When carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy. The chemical reaction is: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l) If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears. CaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq) Other gases listed: - SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082. - NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn't produce a milky precipitate with limewater as characteristically as CO\u2082. - CO (Carbon monoxide) is a neutral gas and does not react with limewater. Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.","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\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/","og_locale":"en_US","og_type":"article","og_title":"Two reactants in a flask produce bubbles of gas that turn limewater mi","og_description":"The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082). When carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy. The chemical reaction is: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l) If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears. CaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq) Other gases listed: - SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082. - NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn't produce a milky precipitate with limewater as characteristically as CO\u2082. - CO (Carbon monoxide) is a neutral gas and does not react with limewater. Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T11:29:49+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\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/","url":"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/","name":"Two reactants in a flask produce bubbles of gas that turn limewater mi","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T11:29:49+00:00","dateModified":"2025-06-01T11:29:49+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The gas that turns limewater milky is CO\u2082. Limewater is a dilute aqueous solution of calcium hydroxide, Ca(OH)\u2082. It is a common test reagent for carbon dioxide (CO\u2082). When carbon dioxide gas is bubbled through limewater, it reacts with calcium hydroxide to form a precipitate of calcium carbonate (CaCO\u2083), which is insoluble in water and makes the solution appear milky or cloudy. The chemical reaction is: Ca(OH)\u2082(aq) + CO\u2082(g) \u2192 CaCO\u2083(s) + H\u2082O(l) If excess carbon dioxide is bubbled through the milky solution, the calcium carbonate precipitate reacts further to form soluble calcium bicarbonate, Ca(HCO\u2083)\u2082, and the milky appearance disappears. CaCO\u2083(s) + CO\u2082(g) + H\u2082O(l) \u2192 Ca(HCO\u2083)\u2082(aq) Other gases listed: - SO\u2082 (Sulfur dioxide) also reacts with limewater, but forms calcium sulfite (CaSO\u2083), which is also insoluble and causes turbidity. However, the reaction with CO\u2082 is the most common and characteristic test for CO\u2082. - NO\u2082 (Nitrogen dioxide) is an acidic gas and would react with Ca(OH)\u2082, but it typically doesn't produce a milky precipitate with limewater as characteristically as CO\u2082. - CO (Carbon monoxide) is a neutral gas and does not react with limewater. Given the standard chemical tests, turning limewater milky is the definitive test for CO\u2082.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/two-reactants-in-a-flask-produce-bubbles-of-gas-that-turn-limewater-mi\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CISF-AC-EXE","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cisf-ac-exe\/"},{"@type":"ListItem","position":3,"name":"Two reactants in a flask produce bubbles of gas that turn limewater mi"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/92647","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=92647"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/92647\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=92647"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=92647"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=92647"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}