{"id":85383,"date":"2025-06-01T03:15:03","date_gmt":"2025-06-01T03:15:03","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85383"},"modified":"2025-06-01T03:15:03","modified_gmt":"2025-06-01T03:15:03","slug":"which-one-of-the-following-is-not-true-for-anodizing-process","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/","title":{"rendered":"Which one of the following is not true for anodizing process?"},"content":{"rendered":"

Which one of the following is not<\/i> true for anodizing process?<\/p>\n

[amp_mcq option1=”It makes aluminium corrosion resistant.” option2=”Metals like aluminium, titanium and magnesium can be anodized.” option3=”Clean aluminium article is the anode and oxygen gas is evolved at the cathode.” option4=”It is used in aircraft industry.” correct=”option3″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CDS-1 – 2023<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nAnodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.
\nA) It makes aluminium corrosion resistant. This is true. The artificially thickened oxide layer is more robust and protective than the natural oxide layer, providing enhanced corrosion resistance.
\nB) Metals like aluminium, titanium and magnesium can be anodized. This is true. These are common metals that form stable oxide layers and are frequently anodized.
\nC) Clean aluminium article is the anode and oxygen gas is evolved at the cathode. In the anodizing process, the aluminium article to be anodized is made the anode (positive electrode). Oxidation occurs at the anode, forming the oxide layer on the aluminium surface. The cathode (negative electrode) is typically an inert material like graphite or lead. At the cathode, reduction occurs, which involves the reduction of water to hydrogen gas and hydroxide ions ($2H_2O + 2e^- \\rightarrow H_2 + 2OH^-$) or the reduction of H\u207a ions to hydrogen gas ($2H^+ + 2e^- \\rightarrow H_2$). Oxygen gas is evolved at the *anode* if the process involves the electrolysis of water ($2H_2O \\rightarrow O_2 + 4H^+ + 4e^-$) as part of the overall reaction, which contributes to the oxide layer formation ($2Al + 3H_2O \\rightarrow Al_2O_3 + 6H^+$). However, the primary anodic reaction is the formation of Al\u2082O\u2083. Oxygen gas evolution typically occurs at the cathode, especially if there are other species present, or as a side reaction. More accurately, hydrogen gas is evolved at the cathode. Therefore, the statement that oxygen gas is evolved at the cathode is *not* true.
\nD) It is used in aircraft industry. This is true. Anodizing is widely used in the aerospace industry to improve the corrosion resistance, wear resistance, and paint adhesion of aluminium alloys used in aircraft components.
\nThe statement that is NOT true is C, specifically regarding oxygen evolution at the cathode.
\n<\/section>\n
\n– In anodizing, the metal article is the anode.
\n– Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing.
\n– Hydrogen gas is typically evolved at the cathode during anodizing.
\n<\/section>\n
\nThe electrolyte used in anodizing is typically an acidic solution (e.g., sulfuric acid, chromic acid, oxalic acid). The structure and properties of the anodic oxide layer depend on the type of electrolyte and process parameters. The porous nature of the oxide layer allows for subsequent dyeing if required.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

Which one of the following is not true for anodizing process? [amp_mcq option1=”It makes aluminium corrosion resistant.” option2=”Metals like aluminium, titanium and magnesium can be anodized.” option3=”Clean aluminium article is the anode and oxygen gas is evolved at the cathode.” option4=”It is used in aircraft industry.” correct=”option3″] This question was previously asked in UPSC CDS-1 … <\/p>\n

Detailed SolutionWhich one of the following is not true for anodizing process?<\/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":[1105,1096,1109],"class_list":["post-85383","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-1","tag-1105","tag-chemistry","tag-metals-minerals-ores-properties-uses","no-featured-image-padding"],"yoast_head":"\nWhich one of the following is not true for anodizing process?<\/title>\n<meta name=\"description\" content=\"Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. A) It makes aluminium corrosion resistant. This is true. The artificially thickened oxide layer is more robust and protective than the natural oxide layer, providing enhanced corrosion resistance. B) Metals like aluminium, titanium and magnesium can be anodized. This is true. These are common metals that form stable oxide layers and are frequently anodized. C) Clean aluminium article is the anode and oxygen gas is evolved at the cathode. In the anodizing process, the aluminium article to be anodized is made the anode (positive electrode). Oxidation occurs at the anode, forming the oxide layer on the aluminium surface. The cathode (negative electrode) is typically an inert material like graphite or lead. At the cathode, reduction occurs, which involves the reduction of water to hydrogen gas and hydroxide ions ($2H_2O + 2e^- rightarrow H_2 + 2OH^-$) or the reduction of H\u207a ions to hydrogen gas ($2H^+ + 2e^- rightarrow H_2$). Oxygen gas is evolved at the *anode* if the process involves the electrolysis of water ($2H_2O rightarrow O_2 + 4H^+ + 4e^-$) as part of the overall reaction, which contributes to the oxide layer formation ($2Al + 3H_2O rightarrow Al_2O_3 + 6H^+$). However, the primary anodic reaction is the formation of Al\u2082O\u2083. Oxygen gas evolution typically occurs at the cathode, especially if there are other species present, or as a side reaction. More accurately, hydrogen gas is evolved at the cathode. Therefore, the statement that oxygen gas is evolved at the cathode is *not* true. D) It is used in aircraft industry. This is true. Anodizing is widely used in the aerospace industry to improve the corrosion resistance, wear resistance, and paint adhesion of aluminium alloys used in aircraft components. The statement that is NOT true is C, specifically regarding oxygen evolution at the cathode. - In anodizing, the metal article is the anode. - Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing. - Hydrogen gas is typically evolved at the cathode during anodizing.\" \/>\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\/which-one-of-the-following-is-not-true-for-anodizing-process\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Which one of the following is not true for anodizing process?\" \/>\n<meta property=\"og:description\" content=\"Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. A) It makes aluminium corrosion resistant. This is true. The artificially thickened oxide layer is more robust and protective than the natural oxide layer, providing enhanced corrosion resistance. B) Metals like aluminium, titanium and magnesium can be anodized. This is true. These are common metals that form stable oxide layers and are frequently anodized. C) Clean aluminium article is the anode and oxygen gas is evolved at the cathode. In the anodizing process, the aluminium article to be anodized is made the anode (positive electrode). Oxidation occurs at the anode, forming the oxide layer on the aluminium surface. The cathode (negative electrode) is typically an inert material like graphite or lead. At the cathode, reduction occurs, which involves the reduction of water to hydrogen gas and hydroxide ions ($2H_2O + 2e^- rightarrow H_2 + 2OH^-$) or the reduction of H\u207a ions to hydrogen gas ($2H^+ + 2e^- rightarrow H_2$). Oxygen gas is evolved at the *anode* if the process involves the electrolysis of water ($2H_2O rightarrow O_2 + 4H^+ + 4e^-$) as part of the overall reaction, which contributes to the oxide layer formation ($2Al + 3H_2O rightarrow Al_2O_3 + 6H^+$). However, the primary anodic reaction is the formation of Al\u2082O\u2083. Oxygen gas evolution typically occurs at the cathode, especially if there are other species present, or as a side reaction. More accurately, hydrogen gas is evolved at the cathode. Therefore, the statement that oxygen gas is evolved at the cathode is *not* true. D) It is used in aircraft industry. This is true. Anodizing is widely used in the aerospace industry to improve the corrosion resistance, wear resistance, and paint adhesion of aluminium alloys used in aircraft components. The statement that is NOT true is C, specifically regarding oxygen evolution at the cathode. - In anodizing, the metal article is the anode. - Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing. - Hydrogen gas is typically evolved at the cathode during anodizing.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:15:03+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=\"2 minutes\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Which one of the following is not true for anodizing process?","description":"Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. A) It makes aluminium corrosion resistant. This is true. The artificially thickened oxide layer is more robust and protective than the natural oxide layer, providing enhanced corrosion resistance. B) Metals like aluminium, titanium and magnesium can be anodized. This is true. These are common metals that form stable oxide layers and are frequently anodized. C) Clean aluminium article is the anode and oxygen gas is evolved at the cathode. In the anodizing process, the aluminium article to be anodized is made the anode (positive electrode). Oxidation occurs at the anode, forming the oxide layer on the aluminium surface. The cathode (negative electrode) is typically an inert material like graphite or lead. At the cathode, reduction occurs, which involves the reduction of water to hydrogen gas and hydroxide ions ($2H_2O + 2e^- rightarrow H_2 + 2OH^-$) or the reduction of H\u207a ions to hydrogen gas ($2H^+ + 2e^- rightarrow H_2$). Oxygen gas is evolved at the *anode* if the process involves the electrolysis of water ($2H_2O rightarrow O_2 + 4H^+ + 4e^-$) as part of the overall reaction, which contributes to the oxide layer formation ($2Al + 3H_2O rightarrow Al_2O_3 + 6H^+$). However, the primary anodic reaction is the formation of Al\u2082O\u2083. Oxygen gas evolution typically occurs at the cathode, especially if there are other species present, or as a side reaction. More accurately, hydrogen gas is evolved at the cathode. Therefore, the statement that oxygen gas is evolved at the cathode is *not* true. D) It is used in aircraft industry. This is true. Anodizing is widely used in the aerospace industry to improve the corrosion resistance, wear resistance, and paint adhesion of aluminium alloys used in aircraft components. The statement that is NOT true is C, specifically regarding oxygen evolution at the cathode. - In anodizing, the metal article is the anode. - Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing. - Hydrogen gas is typically evolved at the cathode during anodizing.","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\/which-one-of-the-following-is-not-true-for-anodizing-process\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following is not true for anodizing process?","og_description":"Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. A) It makes aluminium corrosion resistant. This is true. 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Oxygen gas is evolved at the *anode* if the process involves the electrolysis of water ($2H_2O rightarrow O_2 + 4H^+ + 4e^-$) as part of the overall reaction, which contributes to the oxide layer formation ($2Al + 3H_2O rightarrow Al_2O_3 + 6H^+$). However, the primary anodic reaction is the formation of Al\u2082O\u2083. Oxygen gas evolution typically occurs at the cathode, especially if there are other species present, or as a side reaction. More accurately, hydrogen gas is evolved at the cathode. Therefore, the statement that oxygen gas is evolved at the cathode is *not* true. D) It is used in aircraft industry. This is true. Anodizing is widely used in the aerospace industry to improve the corrosion resistance, wear resistance, and paint adhesion of aluminium alloys used in aircraft components. The statement that is NOT true is C, specifically regarding oxygen evolution at the cathode. - In anodizing, the metal article is the anode. - Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing. - Hydrogen gas is typically evolved at the cathode during anodizing.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T03:15:03+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/","name":"Which one of the following is not true for anodizing process?","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T03:15:03+00:00","dateModified":"2025-06-01T03:15:03+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. A) It makes aluminium corrosion resistant. This is true. The artificially thickened oxide layer is more robust and protective than the natural oxide layer, providing enhanced corrosion resistance. B) Metals like aluminium, titanium and magnesium can be anodized. This is true. These are common metals that form stable oxide layers and are frequently anodized. C) Clean aluminium article is the anode and oxygen gas is evolved at the cathode. In the anodizing process, the aluminium article to be anodized is made the anode (positive electrode). Oxidation occurs at the anode, forming the oxide layer on the aluminium surface. The cathode (negative electrode) is typically an inert material like graphite or lead. At the cathode, reduction occurs, which involves the reduction of water to hydrogen gas and hydroxide ions ($2H_2O + 2e^- \\rightarrow H_2 + 2OH^-$) or the reduction of H\u207a ions to hydrogen gas ($2H^+ + 2e^- \\rightarrow H_2$). 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The statement that is NOT true is C, specifically regarding oxygen evolution at the cathode. - In anodizing, the metal article is the anode. - Anodizing enhances corrosion resistance, wear resistance, and allows for dyeing. - Hydrogen gas is typically evolved at the cathode during anodizing.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-is-not-true-for-anodizing-process\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CDS-1","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cds-1\/"},{"@type":"ListItem","position":3,"name":"Which one of the following is not true for anodizing process?"}]},{"@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\/85383","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=85383"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/85383\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=85383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=85383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=85383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}