{"id":2070,"date":"2026-10-14T17:03:49","date_gmt":"2026-10-14T16:03:49","guid":{"rendered":"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-ascensao-capilar\/"},"modified":"2026-10-14T17:03:49","modified_gmt":"2026-10-14T16:03:49","slug":"calculadora-ascensao-capilar","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-ascensao-capilar\/","title":{"rendered":"Calculadora de ascens\u00e3o capilar"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">Calcule a ascens\u00e3o capilar a partir da tens\u00e3o superficial, da densidade e do raio do tubo<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"2070\" data-favorite-title=\"Ascens\u00e3o capilar\" data-favorite-url=\"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-ascensao-capilar\/\" data-favorite-excerpt=\"Calcule at\u00e9 onde um l\u00edquido sobe (ou desce) em um tubo capilar usando a lei de Jurin. Informe a tens\u00e3o superficial, a densidade do l\u00edquido, o raio do tubo, o \u00e2ngulo de contato e a gravidade para obter a ascens\u00e3o capilar em mm, cm, m ou in.\" aria-label=\"Adicionar aos favoritos\" data-favorite-icon=\"icon icon-molecule\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-ascensao-capilar\/\" method=\"POST\" class=\"calculator\" id=\"calculator-2070\" data-post=\"2070\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Campos de entrada<\/legend><div class=\"field has-term\" id=\"input-1\"><label for=\"field-1\">Tens\u00e3o superficial (\u03b3)<\/label><div class=\"term\">\u03b3<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"tenso_superficial_\" id=\"field-1\" aria-describedby=\"calc-info-1\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 72.8\" min=\"0\" value=\"72.8\"\/><div class=\"grid grid-cols-1\"><select id=\"field-2\" name=\"unidade\" aria-label=\"Unidade\"><option value=\"mN_m\" selected>mN\/m<\/option><option value=\"N_m\">N\/m<\/option><option value=\"dyn_cm\">dyn\/cm<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-1\">Tens\u00e3o superficial do l\u00edquido em contato com o ar. \u00c1gua \u2248 72,8 mN\/m, etanol \u2248 22,3 mN\/m, merc\u00fario \u2248 486 mN\/m (todos a 20 \u00b0C).<\/small><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-3\">Densidade do l\u00edquido (\u03c1)<\/label><div class=\"term\">\u03c1<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"densidade_do_lquido_\" id=\"field-3\" aria-describedby=\"calc-info-3\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 998\" min=\"0\" value=\"998\"\/><div class=\"grid grid-cols-1\"><select id=\"field-4\" name=\"unidade\" aria-label=\"Unidade\"><option value=\"kg_m3\" selected>kg\/m\u00b3<\/option><option value=\"g_cm3\">g\/cm\u00b3<\/option><option value=\"lb_ft3\">lb\/ft\u00b3<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-3\">Densidade do l\u00edquido, e n\u00e3o a do ar ao redor. \u00c1gua \u2248 998 kg\/m\u00b3 a 20 \u00b0C, merc\u00fario \u2248 13546 kg\/m\u00b3.<\/small><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-5\">Raio do tubo (r)<\/label><div class=\"term\">r<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"raio_do_tubo_r\" id=\"field-5\" aria-describedby=\"calc-info-5\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 0.5\" min=\"0\" value=\"0.5\"\/><div class=\"grid grid-cols-1\"><select id=\"field-6\" name=\"unidade\" aria-label=\"Unidade\"><option value=\"mm\" selected>mm<\/option><option value=\"um\">\u00b5m<\/option><option value=\"cm\">cm<\/option><option value=\"m\">m<\/option><option value=\"in\">in<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-5\">Raio interno do tubo capilar. Um tubo com di\u00e2metro interno de 1 mm tem raio de 0,5 mm.<\/small><\/div><div class=\"field has-term\" id=\"input-4\"><label for=\"field-7\">\u00c2ngulo de contato (\u03b8)<\/label><div class=\"term\">\u03b8<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"ngulo_de_contato_\" id=\"field-7\" aria-describedby=\"calc-unit-7 calc-info-7\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 0\" min=\"0\" max=\"180\" value=\"0\"\/><div class=\"unit\" id=\"calc-unit-7\">\u00b0<\/div><small id=\"calc-info-7\">\u00c2ngulo entre a superf\u00edcie do l\u00edquido e a parede do tubo. \u00c1gua em vidro limpo \u2248 0\u00b0 (molha), merc\u00fario em vidro \u2248 140\u00b0 (n\u00e3o molha, provocando depress\u00e3o).<\/small><\/div><div class=\"field has-term\" id=\"input-5\"><label for=\"field-8\">Acelera\u00e7\u00e3o da gravidade (g)<\/label><div class=\"term\">g<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"acelerao_da_gravidade_g\" id=\"field-8\" aria-describedby=\"calc-unit-8 calc-info-8\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 9.81\" min=\"0\" value=\"9.81\"\/><div class=\"unit\" id=\"calc-unit-8\">m\/s\u00b2<\/div><small id=\"calc-info-8\">Terra \u2248 9,81 m\/s\u00b2, Lua \u2248 1,62 m\/s\u00b2. Um g maior reduz a ascens\u00e3o.<\/small><\/div><div class=\"field is-single\" id=\"input-6\"><label for=\"field-9\">Mostrar ascens\u00e3o capilar em<\/label><div class=\"grid grid-cols-1\"><select id=\"field-9\" name=\"mostrar_ascenso_capilar_em\"><option value=\"mm\" selected>mil\u00edmetros (mm)<\/option><option value=\"cm\">cent\u00edmetros (cm)<\/option><option value=\"m\">metros (m)<\/option><option value=\"in\">polegadas (in)<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Recalcular\" id=\"calculate-button\" data-post=\"2070\">Calcular<\/button><button type=\"reset\">Redefinir<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calcular automaticamente<\/label><small>Se ativado, o resultado \u00e9 atualizado automaticamente quando voc\u00ea altera qualquer valor.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Resultados da ascens\u00e3o capilar<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Ascens\u00e3o \/ depress\u00e3o capilar (h)<\/span><span class=\"result-term\">h<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-2\"><span class=\"field-title\"><span>Ascens\u00e3o ou depress\u00e3o e outras unidades<\/span><\/span><span class=\"field-value\" id=\"result-2\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-3\"><span class=\"field-title\"><span>Detalhes do c\u00e1lculo<\/span><\/span><span class=\"field-value\" id=\"result-3\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-4\"><span class=\"field-title\"><span>Sobre a a\u00e7\u00e3o capilar<\/span><\/span><span class=\"field-value\" id=\"result-4\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copiar link para este c\u00e1lculo<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Deixar um coment\u00e1rio<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"2070\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">O que voc\u00ea achou deste resultado?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Curti <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">\u00datil <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confuso <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Decepcionado <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Impreciso <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Ascens\u00e3o capilar<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">F\u00f3rmula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[ h = \\frac{2\\,\\gamma\\,\\cos\\theta}{\\rho\\, g\\, r} \\\\\\]\n\\[ \\Delta p = \\frac{2\\,\\gamma\\,\\cos\\theta}{r} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Onde:<\/strong><\/p>\n<ul>\n<li>\\(h\\) \u2014 ascens\u00e3o ou depress\u00e3o da coluna de l\u00edquido (m)<\/li>\n<li>\\(\\gamma\\) \u2014 tens\u00e3o superficial do l\u00edquido em contato com o ar (N\/m)<\/li>\n<li>\\(\\theta\\) \u2014 \u00e2ngulo de contato entre o l\u00edquido e a parede do tubo (\u00b0)<\/li>\n<li>\\(\\rho\\) \u2014 densidade do l\u00edquido (kg\/m\u00b3)<\/li>\n<li>\\(g\\) \u2014 acelera\u00e7\u00e3o da gravidade (m\/s\u00b2)<\/li>\n<li>\\(r\\) \u2014 raio interno do tubo capilar (m)<\/li>\n<\/ul>\n<p>A primeira equa\u00e7\u00e3o \u00e9 a <strong>lei de Jurin<\/strong>: ela resulta do equil\u00edbrio entre a for\u00e7a capilar para cima \\(2\\pi r\\,\\gamma\\cos\\theta\\) e o peso \\(\\rho g \\pi r^2 h\\) da coluna de l\u00edquido. A segunda fornece o salto de press\u00e3o capilar (de Laplace) atrav\u00e9s do menisco curvado, que \u00e9 o que provoca o movimento.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-2\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Ascens\u00e3o capilar \u2013 Exemplo de c\u00e1lculo<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Exemplo:<\/strong> \u00e1gua a 20 \u00b0C (tens\u00e3o superficial de 72,8 mN\/m e densidade de 998 kg\/m\u00b3) sobe em um capilar de vidro limpo com raio interno de 0,5 mm. A \u00e1gua molha perfeitamente o vidro limpo, ent\u00e3o o \u00e2ngulo de contato \u00e9 0\u00b0, e a gravidade \u00e9 9,81 m\/s\u00b2.<\/p>\n<p>\\[ \\gamma = 72.8\\ \\text{mN\/m} = 0.0728\\ \\text{N\/m}, \\quad r = 0.5\\ \\text{mm} = 5\\times10^{-4}\\ \\text{m} \\]<br \/>\n\\[ h = \\frac{2 \\times 0.0728 \\times \\cos 0\u00b0}{998 \\times 9.81 \\times 5\\times10^{-4}} = \\frac{0.1456}{4.895} \\approx 0.02974\\ \\text{m} \\]<br \/>\n\\[ h \\approx 29.74\\ \\text{mm} \\approx 2.97\\ \\text{cm} \\approx 1.17\\ \\text{in} \\]\n<\/p>\n<p><strong>Resultado:<\/strong> a \u00e1gua sobe cerca de <strong>29,74 mm<\/strong> (\u2248 2,97 cm) acima do n\u00edvel da \u00e1gua ao redor \u2014 exatamente o que a calculadora mostra com os valores padr\u00e3o.<\/p>\n<p>\n\r\n<\/section>\n<h2>Como usar a calculadora de ascens\u00e3o capilar<\/h2>\n<ol>\n<li>Informe a <strong>tens\u00e3o superficial (\u03b3)<\/strong> do l\u00edquido e escolha sua unidade (mN\/m, N\/m ou dyn\/cm). A \u00e1gua a 20 \u00b0C tem cerca de 72,8 mN\/m.<\/li>\n<li>Informe a <strong>densidade do l\u00edquido (\u03c1)<\/strong> e sua unidade (kg\/m\u00b3, g\/cm\u00b3 ou lb\/ft\u00b3). Use a densidade do l\u00edquido, n\u00e3o a do ar ao redor.<\/li>\n<li>Informe o <strong>raio do tubo (r)<\/strong> \u2014 lembre-se de que se trata do raio, ent\u00e3o um tubo com di\u00e2metro interno de 1 mm corresponde a 0,5 mm. Escolha mm, \u00b5m, cm, m ou in.<\/li>\n<li>Defina o <strong>\u00e2ngulo de contato (\u03b8)<\/strong> em graus: 0\u00b0 para a \u00e1gua no vidro limpo, cerca de 140\u00b0 para o merc\u00fario no vidro (o que produz depress\u00e3o em vez de ascens\u00e3o).<\/li>\n<li>Ajuste a <strong>acelera\u00e7\u00e3o da gravidade (g)<\/strong> se necess\u00e1rio; 9,81 m\/s\u00b2 \u00e9 o padr\u00e3o da Terra, e 1,62 m\/s\u00b2 aproxima a da Lua.<\/li>\n<li>Escolha a unidade de sa\u00edda em <strong>Mostrar ascens\u00e3o capilar em<\/strong> (mm, cm, m ou in) \u2014 a ascens\u00e3o cresce rapidamente quanto mais estreito o tubo, ent\u00e3o troque de unidade se o n\u00famero ficar dif\u00edcil de ler.<\/li>\n<\/ol>\n<p>O resultado tem sinal: um valor positivo indica ascens\u00e3o acima do n\u00edvel do l\u00edquido ao redor, e um valor negativo indica depress\u00e3o abaixo dele.<\/p>\n<h2>O que \u00e9 ascens\u00e3o capilar e por que ela acontece?<\/h2>\n<p>A ascens\u00e3o capilar \u00e9 o fen\u00f4meno em que um l\u00edquido sobe por um tubo estreito (um <em>capilar<\/em>) mergulhado nele, aparentemente desafiando a gravidade. Ela \u00e9 causada pela <strong>tens\u00e3o superficial<\/strong>: as mol\u00e9culas na superf\u00edcie do l\u00edquido puxam o menisco para fora ao longo da parede do tubo e, se o l\u00edquido molha a parede (\u00e2ngulo de contato menor que 90\u00b0), o menisco \u00e9 c\u00f4ncavo e sua curvatura gera um d\u00e9ficit de press\u00e3o que suga o l\u00edquido para cima. A coluna para de subir quando seu peso equilibra exatamente a for\u00e7a capilar \u2014 esse equil\u00edbrio \u00e9 a lei de Jurin.<\/p>\n<p>O tra\u00e7o mais marcante da f\u00f3rmula \u00e9 a proporcionalidade inversa ao raio do tubo: <em>reduzir o raio \u00e0 metade dobra a ascens\u00e3o<\/em>. A \u00e1gua em um tubo de 0,5 mm sobe apenas cerca de 3 cm, mas em um poro de 10 \u00b5m ela atinge aproximadamente 1,5 m. Essa rela\u00e7\u00e3o explica por que as toalhas de papel absorvem respingos, por que pavios e esponjas funcionam e como as \u00e1rvores elevam \u00e1gua por dezenas de metros atrav\u00e9s de canais microsc\u00f3picos do xilema \u2014 a capilaridade, junto com a osmose e a transpira\u00e7\u00e3o, \u00e9 um dos principais mecanismos de transporte nas plantas.<\/p>\n<p>O \u00e2ngulo de contato determina a dire\u00e7\u00e3o do efeito. L\u00edquidos que molham (\\(\\theta &lt; 90\u00b0\\), \u00e1gua no vidro) sobem; com \\(\\theta = 90\u00b0\\) a superf\u00edcie permanece plana; e l\u00edquidos que n\u00e3o molham (\\(\\theta &gt; 90\u00b0\\), merc\u00fario no vidro) sofrem <strong>depress\u00e3o<\/strong> abaixo do n\u00edvel ao redor, porque \\(\\cos\\theta\\) \u00e9 negativo. A calculadora indica o sinal automaticamente e diz se voc\u00ea tem uma ascens\u00e3o ou uma depress\u00e3o. Ela tamb\u00e9m mostra o raio de curvatura do menisco (\\(R = r\/\\cos\\theta\\)) e a press\u00e3o capilar \\(\\Delta p\\), que \u00e9 o que um material poroso ou um pavio realmente \"sente\".<\/p>\n<h2>Premissas, limita\u00e7\u00f5es e dicas pr\u00e1ticas<\/h2>\n<ul>\n<li><strong>Geometria do tubo:<\/strong> a f\u00f3rmula assume um cilindro circular vertical de raio uniforme. Canais quadrados, furos c\u00f4nicos ou redes porosas seguem a f\u00f3rmula apenas de modo aproximado.<\/li>\n<li><strong>Raio pequeno:<\/strong> o menisco \u00e9 tratado como uma calota esf\u00e9rica perfeita, o que \u00e9 preciso quando o raio \u00e9 bem menor que o <em>comprimento capilar<\/em> do l\u00edquido (cerca de 2,7 mm para a \u00e1gua). Em torno de 1 mm, desprezar o volume do menisco introduz um erro de alguns por cento; abaixo de 0,5 mm ele \u00e9 desprez\u00edvel.<\/li>\n<li><strong>\u00c2ngulo de contato constante:<\/strong> as superf\u00edcies reais raramente s\u00e3o perfeitamente limpas ou uniformes, ent\u00e3o o \u00e2ngulo efetivo pode diferir dos valores tabelados. Contamina\u00e7\u00e3o, gordura ou tensoativos podem alterar \\(\\gamma\\) e \\(\\theta\\) de forma expressiva \u2014 adicionar detergente \u00e0 \u00e1gua reduz tanto a tens\u00e3o superficial quanto a ascens\u00e3o.<\/li>\n<li><strong>L\u00edquido em repouso:<\/strong> o resultado \u00e9 a altura de equil\u00edbrio; ele n\u00e3o diz nada sobre a rapidez com que o l\u00edquido sobe (que depende da viscosidade, conforme a equa\u00e7\u00e3o de Washburn).<\/li>\n<li><strong>Temperatura:<\/strong> tanto a tens\u00e3o superficial quanto a densidade variam com a temperatura, ent\u00e3o use valores na temperatura de interesse para obter resultados precisos.<\/li>\n<\/ul>\n<p>Se voc\u00ea estiver trabalhando com outras propriedades de l\u00edquidos ou gases, tamb\u00e9m podem ser \u00fateis a nossa <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/gas-density-calculator\/\">Calculadora de densidade de gases<\/a>, a <a href=\"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-equacao-de-antoine\/\">Calculadora da equa\u00e7\u00e3o de Antoine<\/a> para press\u00f5es de vapor ou a <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/mean-free-path-of-gas-molecules-calculator\/\">Calculadora de livre percurso m\u00e9dio<\/a> em problemas de transporte relacionados.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Calcule at\u00e9 onde um l\u00edquido sobe (ou desce) em um tubo capilar usando a lei de Jurin. Informe a tens\u00e3o superficial, a densidade do l\u00edquido, o raio do tubo, o \u00e2ngulo de contato e a gravidade para obter a ascens\u00e3o capilar em mm, cm, m ou in.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[23],"class_list":["post-2070","post","type-post","status-publish","format-standard","hentry","category-quimica","tag-ligacoes-quimicas"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/users\/3168"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/comments?post=2070"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2070\/revisions"}],"predecessor-version":[{"id":2652,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2070\/revisions\/2652"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/media?parent=2070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/categories?post=2070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/tags?post=2070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}