{"id":196323,"date":"2025-03-04T16:48:46","date_gmt":"2025-03-04T16:48:46","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=196323"},"modified":"2025-03-04T16:48:49","modified_gmt":"2025-03-04T16:48:49","slug":"ironiii-ion-fe3-reacts-with-thiocyanate-ion-scn-to-form-a-red-complex-ion-with-the-formula-fescn2","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/04\/ironiii-ion-fe3-reacts-with-thiocyanate-ion-scn-to-form-a-red-complex-ion-with-the-formula-fescn2\/","title":{"rendered":"Iron(III) ion (Fe3+) reacts with thiocyanate ion (SCN) to form a red complex ion with the formula [FeSCN2+"},"content":{"rendered":"\n

Iron(III) ion (Fe3+) reacts with thiocyanate ion (SCN) to form a red complex ion with the formula [FeSCN2+. The net ionic equation describing this reaction is given in Equation 10.<\/p>\n\n\n\n

Fe3+ (aq, It. yellow) + SCN-(aq, colorless) = (FeSCN]2+ (aq, red) (Eq. 10)<\/p>\n\n\n\n

A student studying this equilibrium begins with an equilibrium mixture that is light pink.<\/p>\n\n\n\n

(1) What change will the student observe when a solution containing Fe+ ion is added to this mixture?<\/p>\n\n\n\n

The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n

When a solution containing Fe\u00b3\u207a ions is added to the equilibrium mixture of the reaction<\/p>\n\n\n\n

[
Fe^{3+} (aq, \\text{yellow}) + SCN^- (aq, \\text{colorless}) \\rightleftharpoons [FeSCN]^{2+} (aq, \\text{red}),
]<\/p>\n\n\n\n

the student will observe a shift toward the formation of more red [FeSCN]\u00b2\u207a complex. This occurs due to a principle known as Le Chatelier’s Principle<\/strong>, which states that if a system at equilibrium is disturbed by adding more of one of the reactants, the system will adjust to counteract that disturbance by shifting the equilibrium position to favor the side that consumes the added component.<\/p>\n\n\n\n

In this case, the student starts with a light pink solution, which indicates the presence of both Fe\u00b3\u207a and [FeSCN]\u00b2\u207a, though in relatively lower concentrations. Upon adding more Fe\u00b3\u207a, the system will respond by using the added Fe\u00b3\u207a to produce more of the red [FeSCN]\u00b2\u207a complex. As a result, the solution will become darker red in color as the concentration of the red complex increases.<\/p>\n\n\n\n

This shift happens because, according to the equation, Fe\u00b3\u207a and SCN\u207b react to form [FeSCN]\u00b2\u207a. Increasing the concentration of Fe\u00b3\u207a increases the rate at which the red complex is formed, thus leading to a deeper red solution. The equilibrium shifts to the right, meaning more [FeSCN]\u00b2\u207a is produced until a new equilibrium is reached.<\/p>\n\n\n\n

In summary, when Fe\u00b3\u207a is added to the equilibrium mixture, the student will see a color change toward a darker red. This happens because the system shifts to produce more [FeSCN]\u00b2\u207a in response to the increased concentration of Fe\u00b3\u207a, according to Le Chatelier\u2019s Principle.<\/p>\n\n\n\n

Now, I will generate an image showing the colors of the reactants and products of this equilibrium.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The image above illustrates the equilibrium of the reaction, showing the transition from yellow Fe\u00b3\u207a and colorless SCN\u207b ions to the red [FeSCN]\u00b2\u207a complex. As more Fe\u00b3\u207a ions are added, the solution shifts towards a deeper red color, reflecting the formation of more [FeSCN]\u00b2\u207a, in line with the explanation I provided earlier. <\/p>\n","protected":false},"excerpt":{"rendered":"

Iron(III) ion (Fe3+) reacts with thiocyanate ion (SCN) to form a red complex ion with the formula [FeSCN2+. The net ionic equation describing this reaction is given in Equation 10. Fe3+ (aq, It. yellow) + SCN-(aq, colorless) = (FeSCN]2+ (aq, red) (Eq. 10) A student studying this equilibrium begins with an equilibrium mixture that is […]<\/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-196323","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/196323","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=196323"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/196323\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=196323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=196323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=196323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}