{"id":85222,"date":"2025-06-01T03:08:16","date_gmt":"2025-06-01T03:08:16","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85222"},"modified":"2025-06-01T03:08:16","modified_gmt":"2025-06-01T03:08:16","slug":"while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/","title":{"rendered":"While burning hydrocarbon fuels, if we see a yellow flame with lots of"},"content":{"rendered":"

While burning hydrocarbon fuels, if we see a yellow flame with lots of black smoke, it means that the fuel is :<\/p>\n

[amp_mcq option1=”made of saturated hydrocarbons.” option2=”made of unsaturated hydrocarbons.” option3=”burning completely.” option4=”wet.” correct=”option2″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CDS-1 – 2022<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nA yellow flame with lots of black smoke indicates incomplete combustion. This occurs when there is insufficient oxygen for the fuel to burn completely. Unsaturated hydrocarbons, which have a higher carbon-to-hydrogen ratio than saturated hydrocarbons, tend to undergo incomplete combustion more readily and produce sooty flames (yellow flame and black smoke) when the oxygen supply is limited.
\n<\/section>\n
\nComplete combustion produces a clean, often blue, flame and primarily carbon dioxide and water. Incomplete combustion produces a yellow, luminous, and sooty flame, along with carbon monoxide and unburnt carbon particles (soot), which appear as black smoke. The likelihood of incomplete combustion depends on the fuel type and the oxygen supply.
\n<\/section>\n
\nSaturated hydrocarbons (like alkanes) typically burn with cleaner, often blue, flames compared to unsaturated hydrocarbons (like alkenes, alkynes, and aromatic hydrocarbons) which have higher carbon content and are more prone to incomplete combustion leading to sooty, yellow flames.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

While burning hydrocarbon fuels, if we see a yellow flame with lots of black smoke, it means that the fuel is : [amp_mcq option1=”made of saturated hydrocarbons.” option2=”made of unsaturated hydrocarbons.” option3=”burning completely.” option4=”wet.” correct=”option2″] This question was previously asked in UPSC CDS-1 – 2022 Download PDFAttempt Online A yellow flame with lots of black … <\/p>\n

Detailed SolutionWhile burning hydrocarbon fuels, if we see a yellow flame with lots of<\/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":[1108,1096,1330],"class_list":["post-85222","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-1","tag-1108","tag-chemistry","tag-hydrocarbons","no-featured-image-padding"],"yoast_head":"\nWhile burning hydrocarbon fuels, if we see a yellow flame with lots of<\/title>\n<meta name=\"description\" content=\"A yellow flame with lots of black smoke indicates incomplete combustion. This occurs when there is insufficient oxygen for the fuel to burn completely. Unsaturated hydrocarbons, which have a higher carbon-to-hydrogen ratio than saturated hydrocarbons, tend to undergo incomplete combustion more readily and produce sooty flames (yellow flame and black smoke) when the oxygen supply is limited. Complete combustion produces a clean, often blue, flame and primarily carbon dioxide and water. Incomplete combustion produces a yellow, luminous, and sooty flame, along with carbon monoxide and unburnt carbon particles (soot), which appear as black smoke. The likelihood of incomplete combustion depends on the fuel type and the oxygen supply.\" \/>\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\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"While burning hydrocarbon fuels, if we see a yellow flame with lots of\" \/>\n<meta property=\"og:description\" content=\"A yellow flame with lots of black smoke indicates incomplete combustion. This occurs when there is insufficient oxygen for the fuel to burn completely. Unsaturated hydrocarbons, which have a higher carbon-to-hydrogen ratio than saturated hydrocarbons, tend to undergo incomplete combustion more readily and produce sooty flames (yellow flame and black smoke) when the oxygen supply is limited. Complete combustion produces a clean, often blue, flame and primarily carbon dioxide and water. Incomplete combustion produces a yellow, luminous, and sooty flame, along with carbon monoxide and unburnt carbon particles (soot), which appear as black smoke. The likelihood of incomplete combustion depends on the fuel type and the oxygen supply.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:08:16+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":"While burning hydrocarbon fuels, if we see a yellow flame with lots of","description":"A yellow flame with lots of black smoke indicates incomplete combustion. 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The likelihood of incomplete combustion depends on the fuel type and the oxygen supply.","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\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/","og_locale":"en_US","og_type":"article","og_title":"While burning hydrocarbon fuels, if we see a yellow flame with lots of","og_description":"A yellow flame with lots of black smoke indicates incomplete combustion. This occurs when there is insufficient oxygen for the fuel to burn completely. Unsaturated hydrocarbons, which have a higher carbon-to-hydrogen ratio than saturated hydrocarbons, tend to undergo incomplete combustion more readily and produce sooty flames (yellow flame and black smoke) when the oxygen supply is limited. 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The likelihood of incomplete combustion depends on the fuel type and the oxygen supply.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T03:08:16+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\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/","url":"https:\/\/exam.pscnotes.com\/mcq\/while-burning-hydrocarbon-fuels-if-we-see-a-yellow-flame-with-lots-of\/","name":"While burning hydrocarbon fuels, if we see a yellow flame with lots of","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T03:08:16+00:00","dateModified":"2025-06-01T03:08:16+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"A yellow flame with lots of black smoke indicates incomplete combustion. 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