{"id":8943,"date":"2024-08-06T13:40:53","date_gmt":"2024-08-06T16:40:53","guid":{"rendered":"https:\/\/xequematenem.com.br\/blog\/?p=8943"},"modified":"2024-08-06T13:40:53","modified_gmt":"2024-08-06T16:40:53","slug":"questao-82-enem-ppl-2015-caderno-9-branco","status":"publish","type":"post","link":"https:\/\/xequematenem.com.br\/blog\/questao-82-enem-ppl-2015-caderno-9-branco\/","title":{"rendered":"Quest\u00e3o 082 \u2013 ENEM PPL 2015 (Caderno 9 \u2013 BRANCO)"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">A cafe\u00edna \u00e9 um alcaloide, identificado como 1,3,7-trimetilxantina (massa molar igual a 194 g\/mol), cuja estrutura qu\u00edmica cont\u00e9m uma unidade de purina, conforme representado. Esse alcaloide \u00e9 encontrado em grande quantidade nas sementes de caf\u00e9 e nas folhas de ch\u00e1-verde. <strong>Uma x\u00edcara de caf\u00e9 cont\u00e9m, em m\u00e9dia, 80 mg de cafe\u00edna.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"450\" height=\"292\" src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-291.png\" alt=\"\" class=\"wp-image-8944\" style=\"width:374px;height:auto\" title=\"\" srcset=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-291.png 450w, https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-291-300x195.png 300w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Considerando que a x\u00edcara descrita cont\u00e9m um <strong>volume de 200 mL de caf\u00e9, a concentra\u00e7\u00e3o, em mol\/L, de cafe\u00edna nessa x\u00edcara \u00e9 mais pr\u00f3xima de:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A) 0,0004.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B) 0,002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C) 0,4.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">D) 2.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">E) 4.<\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size wp-block-paragraph\"><strong>Solu\u00e7\u00e3o<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Uma x\u00edcara de caf\u00e9 cont\u00e9m 80 mg de cafe\u00edna, o que equivale a 0,08 g. Utilizando a massa molar da cafe\u00edna, que \u00e9 194 g\/mol, podemos converter os 0,08 g para mols da seguinte forma:<\/p>\n\n\n\n<div class=\"wp-block-group is-vertical is-layout-flex wp-container-core-group-is-layout-2c90304e wp-block-group-is-layout-flex\">\n<p class=\"wp-block-paragraph\">194 g &#8212;&#8212;&#8212;&#8211; 1 mol de cafe\u00edna<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">0,08 g &#8212;&#8212;&#8212;- x<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>x = 0,000412&nbsp;mol de cafe\u00edna.<\/strong><\/p>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Se o volume da x\u00edcara \u00e9 de 200 mL (0,2 L) a concentra\u00e7\u00e3o de cafe\u00edna e dada por:<strong> <em>M = n\/V<\/em><\/strong><strong>, <\/strong>em que <strong><em>M<\/em> <\/strong>\u00e9 a concentra\u00e7\u00e3o molar,<strong> <em>n<\/em> <\/strong>\u00e9 o n\u00famero de mol e<strong> <em>V<\/em> <\/strong>o volume:<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img decoding=\"async\" width=\"436\" height=\"80\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-292.png\" alt=\"\" class=\"wp-image-8945 lazyload\" style=\"--smush-placeholder-width: 436px; --smush-placeholder-aspect-ratio: 436\/80;width:316px;height:auto\" title=\"\" data-srcset=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-292.png 436w, https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/08\/image-292-300x55.png 300w\" data-sizes=\"(max-width: 436px) 100vw, 436px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Alternativa B<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A cafe\u00edna \u00e9 um alcaloide, identificado como 1,3,7-trimetilxantina (massa molar igual a 194 g\/mol), cuja estrutura qu\u00edmica cont\u00e9m uma unidade de purina, conforme representado. Esse alcaloide \u00e9 encontrado em grande quantidade nas sementes de caf\u00e9 e nas folhas de ch\u00e1-verde. Uma x\u00edcara de caf\u00e9 cont\u00e9m, em m\u00e9dia, 80 mg de cafe\u00edna. Considerando que a x\u00edcara [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":8944,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[87,94],"tags":[],"area-do-conhecimento":[116,120],"assunto":[],"class_list":["post-8943","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-questoes-ppl","category-2015-questoes-ppl","area-do-conhecimento-ciencias-da-natureza-e-suas-tecnologias","area-do-conhecimento-quimica"],"_links":{"self":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/8943","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/comments?post=8943"}],"version-history":[{"count":1,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/8943\/revisions"}],"predecessor-version":[{"id":8946,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/8943\/revisions\/8946"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/media\/8944"}],"wp:attachment":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/media?parent=8943"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/categories?post=8943"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/tags?post=8943"},{"taxonomy":"area-do-conhecimento","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/area-do-conhecimento?post=8943"},{"taxonomy":"assunto","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/assunto?post=8943"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}