{"id":85597,"date":"2025-06-01T03:22:19","date_gmt":"2025-06-01T03:22:19","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85597"},"modified":"2025-06-01T03:22:19","modified_gmt":"2025-06-01T03:22:19","slug":"which-one-of-the-following-statements-is-correct-22","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-22\/","title":{"rendered":"Which one of the following statements is correct?"},"content":{"rendered":"

Which one of the following statements is correct?<\/p>\n

[amp_mcq option1=”The oxidation number for hydrogen is always zero.” option2=”The oxidation number for hydrogen is always +1.” option3=”The oxidation number for hydrogen is always -1.” option4=”Hydrogen can have more than one oxidation number.” correct=”option4″]<\/p>\n

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This question was previously asked in<\/div>\n
UPSC CDS-2 – 2016<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number.<\/section>\n
The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H\u2082O, HCl, NH\u2083). However, when bonded to more active metals (forming metal hydrides like NaH, CaH\u2082), hydrogen is more electronegative than the metal and has an oxidation number of -1. In its elemental form (H\u2082), the oxidation number is 0.<\/section>\n
The oxidation number reflects the hypothetical charge an atom would have in a molecule if all bonds were ionic. The electronegativity difference between hydrogen and the atom it is bonded to determines whether hydrogen takes a positive or negative oxidation state.<\/section>\n","protected":false},"excerpt":{"rendered":"

Which one of the following statements is correct? [amp_mcq option1=”The oxidation number for hydrogen is always zero.” option2=”The oxidation number for hydrogen is always +1.” option3=”The oxidation number for hydrogen is always -1.” option4=”Hydrogen can have more than one oxidation number.” correct=”option4″] This question was previously asked in UPSC CDS-2 – 2016 Download PDFAttempt Online … <\/p>\n

Detailed SolutionWhich one of the following statements is correct?<\/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":[1088],"tags":[1098,1096,1161],"class_list":["post-85597","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-2","tag-1098","tag-chemistry","tag-hydrogen-and-its-compounds","no-featured-image-padding"],"yoast_head":"\nWhich one of the following statements is correct?<\/title>\n<meta name=\"description\" content=\"Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number. The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H\u2082O, HCl, NH\u2083). However, when bonded to more active metals (forming metal hydrides like NaH, CaH\u2082), hydrogen is more electronegative than the metal and has an oxidation number of -1. In its elemental form (H\u2082), the oxidation number is 0.\" \/>\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-statements-is-correct-22\/\" \/>\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 statements is correct?\" \/>\n<meta property=\"og:description\" content=\"Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number. The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H\u2082O, HCl, NH\u2083). However, when bonded to more active metals (forming metal hydrides like NaH, CaH\u2082), hydrogen is more electronegative than the metal and has an oxidation number of -1. In its elemental form (H\u2082), the oxidation number is 0.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-22\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:22:19+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":"Which one of the following statements is correct?","description":"Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number. The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H\u2082O, HCl, NH\u2083). However, when bonded to more active metals (forming metal hydrides like NaH, CaH\u2082), hydrogen is more electronegative than the metal and has an oxidation number of -1. In its elemental form (H\u2082), the oxidation number is 0.","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-statements-is-correct-22\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following statements is correct?","og_description":"Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number. The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H\u2082O, HCl, NH\u2083). 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