Why Mn2+ ion is almost colourless wheras Mn7+ ion is coloured<\/p>\n\n\n\n
The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n The color of transition metal ions is primarily determined by their electronic configurations and the nature of their d-orbitals. Manganese exists in multiple oxidation states, notably +2 (Mn\u00b2\u207a) and +7 (Mn\u2077\u207a), each exhibiting distinct electronic structures that influence their color properties.<\/p>\n\n\n\n Mn\u00b2\u207a Ion:<\/strong><\/p>\n\n\n\n In the Mn\u00b2\u207a state, manganese has an electron configuration of [Ar] 3d\u2075. This configuration results in a high-spin d\u2075 system, where all five d-orbitals are singly occupied. In an octahedral field, these d-orbitals split into two energy levels: the lower-energy t\u2082g and the higher-energy e_g orbitals. However, due to the high-spin nature of Mn\u00b2\u207a, the energy difference between these levels is minimal, leading to weak d-d transitions. Moreover, the selection rules governing these transitions often render them spin-forbidden, further diminishing their intensity. Consequently, Mn\u00b2\u207a complexes typically appear colorless or exhibit very faint colors.<\/p>\n\n\n\n Mn\u2077\u207a Ion:<\/strong><\/p>\n\n\n\n Conversely, Mn\u2077\u207a possesses an electron configuration of [Ar] 3d\u2070. With no electrons in the d-orbitals, Mn\u2077\u207a cannot undergo d-d transitions. Instead, its color arises from charge transfer transitions, where an electron moves from an oxygen ligand’s orbital to the empty d-orbital of the manganese ion. These transitions are typically allowed and result in the absorption of visible light, imparting a characteristic color to Mn\u2077\u207a compounds. For instance, potassium permanganate (KMnO\u2084), where Mn is in the +7 oxidation state, is deep purple due to such charge transfer transitions.<\/p>\n\n\n\n In summary, the colorless nature of Mn\u00b2\u207a is attributed to its high-spin d\u2075 configuration, leading to weak and often spin-forbidden d-d transitions. In contrast, Mn\u2077\u207a exhibits color due to charge transfer transitions, where electrons move between the metal ion and its ligands, resulting in the absorption of visible light and the manifestation of color.<\/p>\n","protected":false},"excerpt":{"rendered":" Why Mn2+ ion is almost colourless wheras Mn7+ ion is coloured The Correct Answer and Explanation is : The color of transition metal ions is primarily determined by their electronic configurations and the nature of their d-orbitals. Manganese exists in multiple oxidation states, notably +2 (Mn\u00b2\u207a) and +7 (Mn\u2077\u207a), each exhibiting distinct electronic structures that […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-179809","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/179809","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=179809"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/179809\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=179809"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=179809"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=179809"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}