[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-207961-en":3,"doc-seo-207961-105":30,"detail-sidebar-cat-0-en-105":90},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":27,"seo_description":14,"update_tm":28,"read_time":29},207961,549768064622,"Lucas Vance","https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8",4,"Exam","4.1 Electrolysis","Electrolysis is defined as the decomposition of an ionic compound in the molten state or in aqueous solution using an electric current. The notes guide identification of anode and cathode, the role of the electrolyte and mobile ions, and the need for a D.C. supply. It explains electrode products and observations for molten salts, concentrated aqueous sodium chloride (brine), and dilute sulfuric acid with inert platinum or carbon/graphite electrodes, including how ion competition determines hydrogen, metals, oxygen, water, and halogen products.","CAIE IGCSE Chemistry  \n# 4.1 Electrolysis\n\nNotes  \n## Define electrolysis\n\nElectrolysis is the decomposition of an ionic compound, when molten or in aqueoussolution, by an electric current being passed through.  \nIdentify in simple electrolytic cells:  \n● The anode isthe positively charged electrode- attracting negatively chargedions towards it  \n● The cathode isthe negatively charged electrode- attracting positively chargedions towards it  \n● The electrolyte is an ionic compound in the molten or aqueous state thatundergoes electrolysis- Ions in the electrolyte are able to move freely and areattracted towards the electrode with an opposite charge  \n● The electrodes are connected to a direct current (D.C) supply  \nIdentify the products formed atthe electrodes and describe theobservations made during the electrolysis of:  \nDuring electrolysis of molten salts, a metal will form at the cathode and a  \n(a) Molten lead(II) bromide  \nnon-metal forms atthe anode  \n● Molten lead (II) bromide : PbBr2 (l) is an electrolyte from a molten salt  \n● During electrolysis:  \n○ Pb2+ ions will be attracted to the cathode where they gain electrons andbecome Pb atoms, forming lead  \n○ Br – ions will be attracted to the anode where they lose electrons andbecome Br atoms, that then pair up to become Br2 molecules (sincebromine is diatomic), forming bromine  \n## (b) Concentrated aqueous sodium chloride\n\nFor electrolysis of aqueous solutions, more ions will be released in theelectrolyte, since itis dissolved in water:  \n○ H+ from the water andthe positive ions from the ionic compound will beattra– ctedtothe cathode  \n○ OH from the water andthe negative ions from the ionic compound willbe attracted to the anode  \n○ These ions will compete at their electrodes to gain/lose electrons  \n○ At the cathode: (according to the the reactivity series)  \n■ If the metalis more reactive than hydrogen, hydrogen will beproduced.  \n■ If the metal is less reactive than hydrogen, the metal is produced  \n○ At the anode:  \n■ Oxygen and water is produced (from the OH– ions) unless halideions are present  \n■ If halide ions are present, they lose electrons and form theirhalogens  \n● Concentrated aqueous sodium chloride: NaCl (aq) can alsobe referred to as‘brine’  \n● Concentrated aqueous sodium chloride: NaCl (aq) is an electrolyte of anaqueous solution:  \n○ At the cathode:  \n■ Na+ ions and H+ ions are attracted  \n■ Na is more reactive than hydrogen, so hydrogen ions gainselectrons and produces hydrogen H2(g)  \n○ At the anode:  \n■ Cl– and OH– ions are attracted  \n■ Cl– is a halide so will lose electrons and form chlorine gas Cl2(g)  \n○ The Na+ and OH– ions left behind will form NaOH (aq)  \n## (c) Dilute sulfuric acid using inert electrodes made of platinum or carbon/ graphite\n\nDilute sulfuric acid H2SO4 (aq) can alsobe referred to as ‘acidified water’  \n● This electrolysis requires inert (will not react) electrodes made from platinumor graphite  \n● Dilute sulfuric acid H2SO4 (aq) is an electrolyte of an aqueous solution:  \n○ At the cathode:  \n■ H+ ions (from the water and H2SO4) are attracted  \n■ H+ ions gains electrons and becomes hydrogen gas H2  \n○ At the anode:  \n■ OH– and SO4 2– ions are attracted  \n■ Since there are no halide ions, OH– ions will lose electrons andform oxygen gas and water  \nState that metals or hydrogen are formed at the cathode and thatnon-metals (other than hydrogen) are formed atthe anode  \n● At the cathode: (according to the thereactivity series)  \n○ If the metalis more reactive than hydrogen, hydrogen will be produced.  \n○ If the metal is less reactive than hydrogen, the metal is produced  \n● At the anode:  \n○ Oxygen and water is produced (from the OH– ions) unless halide ionsare present  \n○ If halide ions are present, they lose electrons and form their halogens  \n## Predict the identity of the products at each electrode for the electrolysis of\n\na binary compound in the molten state  \n● During electrolysis of molten salts, a metal will format the cat","cbCaicw1pv5PU6IJ","https://ap.wps.com/l/cbCaicw1pv5PU6IJ","pdf",1078776,1,8,"English","en",105,"# 4.1 Electrolysis\n## Define electrolysis\n## Identify products in electrolytic cells\n## Molten salts: lead(II) bromide\n## Concentrated aqueous sodium chloride (brine)\n## Dilute sulfuric acid with inert electrodes\n## Predict electrode products for molten binary compounds\n## Electroplating: purpose and process","[{\"question\":\"What is electrolysis and when does it occur?\",\"answer\":\"Electrolysis is the decomposition of an ionic compound when the compound is molten or dissolved in water, and an electric current is passed through it. The ions must be able to move freely in the electrolyte so they can migrate to the electrodes.\"},{\"question\":\"How are ions arranged and used at the anode and cathode?\",\"answer\":\"In the electrolytic cell, the anode is positively charged and attracts negatively charged ions, while the cathode is negatively charged and attracts positively charged ions. Ions move to the electrode with the opposite charge and then gain or lose electrons to form products.\"},{\"question\":\"What products form at the electrodes during electrolysis of concentrated aqueous sodium chloride (brine)?\",\"answer\":\"At the cathode, Na+ and H+ are attracted; because the metal is more reactive than hydrogen, hydrogen ions gain electrons to form hydrogen gas (H2). At the anode, Cl− and OH− are attracted; without forming NaCl back, Cl− loses electrons to form chlorine gas (Cl2), and the remaining ions form NaOH(aq).\"}]","4.1 Electrolysis | PDF",1788601920,20,{"code":4,"msg":31,"data":32},"ok",{"site_id":24,"language":23,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":85,"head_meta":87,"extra_data":89,"updated_unix":28},"41-electrolysis","",{"@graph":36,"@context":84},[37,53,67],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,51],{"item":41,"name":42,"@type":43,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":50},"https://docshare.wps.com/document/exam/",3,{"item":52,"name":13,"@type":43,"position":11},"https://docshare.wps.com/document/41-electrolysis/207961/",{"url":52,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":61,"encodingFormat":60,"isAccessibleForFree":62,"interactionStatistic":63},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-09-05",true,{"@type":64,"interactionType":65,"userInteractionCount":4},"InteractionCounter",{"@type":66},"ViewAction",{"@type":68,"mainEntity":69},"FAQPage",[70,76,80],{"name":71,"@type":72,"acceptedAnswer":73},"What is electrolysis and when does it occur?","Question",{"text":74,"@type":75},"Electrolysis is the decomposition of an ionic compound when the compound is molten or dissolved in water, and an electric current is passed through it. The ions must be able to move freely in the electrolyte so they can migrate to the electrodes.","Answer",{"name":77,"@type":72,"acceptedAnswer":78},"How are ions arranged and used at the anode and cathode?",{"text":79,"@type":75},"In the electrolytic cell, the anode is positively charged and attracts negatively charged ions, while the cathode is negatively charged and attracts positively charged ions. Ions move to the electrode with the opposite charge and then gain or lose electrons to form products.",{"name":81,"@type":72,"acceptedAnswer":82},"What products form at the electrodes during electrolysis of concentrated aqueous sodium chloride (brine)?",{"text":83,"@type":75},"At the cathode, Na+ and H+ are attracted; because the metal is more reactive than hydrogen, hydrogen ions gain electrons to form hydrogen gas (H2). At the anode, Cl− and OH− are attracted; without forming NaCl back, Cl− loses electrons to form chlorine gas (Cl2), and the remaining ions form NaOH(aq).","https://schema.org",{"og:url":52,"og:type":86,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":88,"canonical":52},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":91},[92,96,100,103,108,113,118,122,126,129,133],{"id":20,"doc_module":4,"doc_module_name":46,"category_name":93,"show_sort_weight":94,"slug":95},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":97,"show_sort_weight":98,"slug":99},"Literature",80,"literature",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":101,"slug":102},70,"exam",{"id":104,"doc_module":4,"doc_module_name":46,"category_name":105,"show_sort_weight":106,"slug":107},5,"Comic",60,"comic",{"id":109,"doc_module":4,"doc_module_name":46,"category_name":110,"show_sort_weight":111,"slug":112},6,"Technology",50,"technology",{"id":114,"doc_module":4,"doc_module_name":46,"category_name":115,"show_sort_weight":116,"slug":117},7,"Healthcare",40,"healthcare",{"id":21,"doc_module":4,"doc_module_name":46,"category_name":119,"show_sort_weight":120,"slug":121},"Research & Report",30,"research-report",{"id":123,"doc_module":4,"doc_module_name":46,"category_name":124,"show_sort_weight":29,"slug":125},9,"Religion & Spirituality","religion-spirituality",{"id":29,"doc_module":4,"doc_module_name":46,"category_name":127,"show_sort_weight":29,"slug":128},"World Cup","world-cup",{"id":130,"doc_module":4,"doc_module_name":46,"category_name":131,"show_sort_weight":130,"slug":132},10,"Lifestyle","lifestyle",{"id":134,"doc_module":4,"doc_module_name":46,"category_name":135,"show_sort_weight":104,"slug":136},19,"General","general"]