{"id":104,"date":"2024-10-24T21:09:42","date_gmt":"2024-10-25T01:09:42","guid":{"rendered":"https:\/\/sites.temple.edu\/chemdemo\/?p=104"},"modified":"2024-10-25T16:22:01","modified_gmt":"2024-10-25T20:22:01","slug":"hcl-cannon-radicals","status":"publish","type":"post","link":"https:\/\/sites.temple.edu\/chemdemo\/2024\/10\/24\/hcl-cannon-radicals\/","title":{"rendered":"HCl Cannon  Radicals"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Equipment<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>One 250-mL Erlenmeyer flask<\/li>\n\n\n\n<li>A #6 stopper with 3 holes<\/li>\n\n\n\n<li>Two graphite electrodes (sized to fit stopper holes and reach the bottom of the flask)<\/li>\n\n\n\n<li>Power supply (capable of approximately 6 volts and 2 amperes)<\/li>\n\n\n\n<li>100-mL clear plastic graduated cylinder (with end spout cut off)<\/li>\n\n\n\n<li>2-hole stopper for the graduated cylinder<\/li>\n\n\n\n<li>Cork for graduated cylinder<\/li>\n\n\n\n<li>Plastic tubing and glass bends to channel gases<\/li>\n\n\n\n<li>Camera flash or intense white light source<\/li>\n\n\n\n<li><strong>Optional<\/strong>: Red and blue filters<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Reagents<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>250 mL of 6 M HCl<\/li>\n\n\n\n<li>250 mL of 6 M NaOH<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Presentation Steps<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Pour the HCl solution into the flask until the level is about 5 cm from the bottom of the stopper.<\/li>\n\n\n\n<li>Firmly place the stopper with electrodes and gas outlet tube onto the flask.<\/li>\n\n\n\n<li>Insert the stopper with the gas inlet and outlet tubes into the graduated cylinder.<\/li>\n\n\n\n<li>Direct the outlet from the graduated cylinder into the NaOH solution to react with any escaping chlorine, converting it into hypochlorite.<\/li>\n\n\n\n<li>Connect the output of the power supply to the electrodes and turn on the power supply.<\/li>\n\n\n\n<li>Adjust the power supply to between 5 and 6 volts, producing approximately 2 amperes of current. Hydrogen and chlorine gas bubbles will begin to form on the electrodes&#8217; surfaces. The solution will turn pale green due to dissolved chlorine.<\/li>\n\n\n\n<li>Allow electrolysis to continue until the graduated cylinder&#8217;s contents are distinctly green (approximately 15-20 minutes).<\/li>\n\n\n\n<li>Turn off the power supply.<\/li>\n\n\n\n<li>Quickly replace the stopper with a cork, gently pressed into the graduated cylinder to prevent rupturing.<\/li>\n\n\n\n<li>Clamp the graduated cylinder into a ring stand, positioning it for a high arc of the cork.<\/li>\n\n\n\n<li>Wearing eye and ear protection, charge a camera flash and flash it next to the tube.<\/li>\n\n\n\n<li>Use filters; the red filter will not initiate the reaction, while the blue filter will transmit sufficient energy to do so.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">Hazards<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Hydrochloric acid can irritate skin and is extremely irritating to eyes and respiratory system; handle in a well-ventilated area.<\/li>\n\n\n\n<li>Solid sodium hydroxide and concentrated solutions can cause severe burns to eyes, skin, and mucous membranes.<\/li>\n\n\n\n<li>The cork may be propelled with sufficient force to cause injury; use caution.<\/li>\n\n\n\n<li>The graduated cylinder may shatter if the cork is seated too firmly and weakens after multiple uses (usually bursts after 3-4 uses).<\/li>\n\n\n\n<li>Hearing protection is recommended for the demonstrator, and the audience should be cautioned to cover their ears.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Chemical Reactions<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>Reaction<\/strong><\/th><th><strong>Type<\/strong><\/th><th><strong>Equation<\/strong><\/th><\/tr><\/thead><tbody><tr><td>Cl\u2082 + light (500 nm) \u2192 2 Cl\u2022<\/td><td>Initiation<\/td><td>Cl\u2082 + light (500 nm) \u2192 2 Cl\u2022<\/td><\/tr><tr><td>Cl\u2022 + H\u2082 \u2192 HCl + H\u2022<\/td><td>Propagation<\/td><td>Cl\u2022 + H\u2082 \u2192 HCl + H\u2022<\/td><\/tr><tr><td>H\u2022 + Cl\u2082 \u2192 HCl + Cl\u2022<\/td><td>Propagation<\/td><td>H\u2022 + Cl\u2082 \u2192 HCl + Cl\u2022<\/td><\/tr><tr><td>2 Cl\u2022 \u2192 Cl\u2082<\/td><td>Possible Termination<\/td><td>2 Cl\u2022 \u2192 Cl\u2082<\/td><\/tr><tr><td>H\u2022 + O\u2082 \u2192 HOO\u2022<\/td><td>Possible Termination<\/td><td>H\u2022 + O\u2082 \u2192 HOO\u2022<\/td><\/tr><tr><td>Cl\u2022 + O\u2082 \u2192 ClO\u2082\u2022<\/td><td>Possible Termination<\/td><td>Cl\u2022 + O\u2082 \u2192 ClO\u2082\u2022<\/td><\/tr><tr><td>Radical + container wall<\/td><td>Possible Termination<\/td><td>Radical + container wall<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">References<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>B. Z. Shakhashiri, <em>Chemical Demonstrations: A Handbook for Teachers of Chemistry<\/em>, Wisconsin, 1983, Vol. 1, pp. 121-123.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Equipment Reagents Presentation Steps Hazards Chemical Reactions Reaction Type Equation Cl\u2082 + light (500 nm) \u2192 2 Cl\u2022 Initiation Cl\u2082 + light (500 nm) \u2192&#8230;<\/p>\n<div class=\"more-link-wrapper\"><a class=\"more-link\" href=\"https:\/\/sites.temple.edu\/chemdemo\/2024\/10\/24\/hcl-cannon-radicals\/\">Continue Reading<span class=\"screen-reader-text\">HCl Cannon  Radicals<\/span><\/a><\/div>\n","protected":false},"author":36673,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-104","post","type-post","status-publish","format-standard","hentry","category-demonstrations","entry"],"_links":{"self":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/users\/36673"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/comments?post=104"}],"version-history":[{"count":1,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/104\/revisions"}],"predecessor-version":[{"id":105,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/104\/revisions\/105"}],"wp:attachment":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/media?parent=104"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/categories?post=104"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/tags?post=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}