{"id":3486,"date":"2025-07-22T10:05:42","date_gmt":"2025-07-22T10:05:42","guid":{"rendered":"https:\/\/odeacademy.in\/?p=3486"},"modified":"2025-07-22T12:54:40","modified_gmt":"2025-07-22T12:54:40","slug":"chemical-reactions-and-equations","status":"publish","type":"post","link":"https:\/\/thequickknowledge.com\/exam\/chemical-reactions-and-equations\/","title":{"rendered":"Chemical Reactions and Equations \u2013 Chemistry | General Science"},"content":{"rendered":"<h4 style=\"text-align: center;\">Chemical Reactions and Equations<\/h4>\n<div class=\"CM8kHf j86kh\" data-hveid=\"CAkQAQ\">\n<div data-expression=\"frac{1}{v} + frac{1}{u} = frac{1}{f}\">\n<hr \/>\n<\/div>\n<\/div>\n<p>Chemical reactions cause change in identity and nature of substances. <strong>Indicators of a chemical reaction<\/strong>: Change in state, Change in color, Evolution of gas, Change in temperature etc.<\/p>\n<p><strong>Types of Chemical Reactions<\/strong><\/p>\n<ul>\n<li><strong>Redox Reaction<\/strong>: 3Fe + 4H\u2082O \u2192 Fe\u2083O\u2084 + 4H\u2082<\/li>\n<li><strong>Combination Reaction<\/strong> &#8211; When two or more substances combine to form a single product.<br \/>\nCaO(s)+H2O(l)\u2192Ca(OH)2 (aq) + Heat<\/li>\n<li><strong>Decomposition Reaction<\/strong> &#8211; A single compound breaks down into <strong data-start=\"1090\" data-end=\"1112\">simpler substances<\/strong>.<\/li>\n<li>(Electrolysis of water produces hydrogen and oxygen gases. Silver chloride turns grey in sunlight, forming silver and chlorine. Silver bromide also decomposes in sunlight similarly.)<br \/>\n(1) CaCO3(s)\u2192 CaO(s)+CO2(g), (2) 2FeSO4 \u2192 Fe2O3 + SO2 + SO3<\/li>\n<li><strong data-start=\"524\" data-end=\"549\">Displacement Reaction<\/strong>: Iron displaces copper from copper sulphate solution. Iron nail turns brown, and the solution\u2019s blue color fades. Zinc and lead are more reactive and can displace copper from compounds.<\/li>\n<li><strong>Double Displacement Reaction<\/strong>: Mixing sodium sulphate and barium chloride forms a white precipitate of barium sulphate.<\/li>\n<li><strong data-start=\"890\" data-end=\"925\">Oxidation and Reduction (Redox)<\/strong>:\n<ul>\n<li><strong data-start=\"932\" data-end=\"949\">Copper powder<\/strong> turns black on heating due to the formation of <strong data-start=\"997\" data-end=\"1017\">copper(II) oxide<\/strong>.<\/li>\n<li data-start=\"930\" data-end=\"1018\">When <strong data-start=\"1029\" data-end=\"1041\">hydrogen<\/strong> is passed over hot copper(II) oxide, it reduces to copper.<\/li>\n<li data-start=\"930\" data-end=\"1018\"><strong>Corrosion:<\/strong> The process where metals (like iron) react with substances such as moisture or acids and deteriorate. It is commonly observed as rusting (iron turns reddish-brown). Silver and copper also tarnish.<\/li>\n<li data-start=\"930\" data-end=\"1018\"><strong data-start=\"508\" data-end=\"521\">Rancidity<\/strong>: Occurs when fats and oils are oxidized, resulting in unpleasant smells and taste. Antioxidants are added to delay rancidity.<\/li>\n<\/ul>\n<\/li>\n<li>\n<p data-start=\"890\" data-end=\"926\">\n<\/li>\n<\/ul>\n<p>Exothermic in nature (releases heat), Calcium hydroxide is used in whitewashing.<\/p>\n<p>g<\/p>\n<hr \/>\n<p><span style=\"color: #ff0000;\"><strong>Related Links<\/strong><\/span><\/p>\n<ul>\n<li><strong>General Science : Questions for Competitive Exams<\/strong> \ud83d\udd17<\/li>\n<\/ul>\n<p><strong><a href=\"https:\/\/thequickknowledge.com\/exam\/general-science\/\">General Science<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/study-materials\/\">Study Materials<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/current-affairs\/\">Current Affairs<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/practice-questions\/\">Practice Questions<\/a>,\u00a0<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Chemical Reactions and Equations Chemical reactions cause change in identity and nature of substances. Indicators of a chemical reaction: Change in state, Change in color, Evolution of gas, Change in temperature etc. Types of Chemical Reactions Redox Reaction: 3Fe + 4H\u2082O \u2192 Fe\u2083O\u2084 + 4H\u2082 Combination Reaction &#8211; When two or more substances combine to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"no-sidebar","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":"disabled","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","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":[137],"tags":[138],"class_list":["post-3486","post","type-post","status-publish","format-standard","hentry","category-general-science","tag-general-science-notes"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/comments?post=3486"}],"version-history":[{"count":3,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3486\/revisions"}],"predecessor-version":[{"id":3495,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3486\/revisions\/3495"}],"wp:attachment":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/media?parent=3486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/categories?post=3486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/tags?post=3486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}