{"id":39242,"date":"2025-06-27T05:07:25","date_gmt":"2025-06-27T05:07:25","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=39242"},"modified":"2025-06-27T05:07:26","modified_gmt":"2025-06-27T05:07:26","slug":"the-specific-heat-of-liquid-mercury-is-140-j-kgac","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/the-specific-heat-of-liquid-mercury-is-140-j-kgac\/","title":{"rendered":"The specific heat of liquid mercury is 140 J\/kg\u00c2\u00b0C."},"content":{"rendered":"\n<p>The specific heat of liquid mercury is 140 J\/kg\u00c2\u00b0C. When 1.0 kg of solid mercury at its melting point of -39\u00c2\u00b0C is placed in a 0.50-kg aluminum calorimeter filled with 1.2 kg of water at 20.0\u00c2\u00b0C, the mercury melts and the final temperature of the combination is found to be 16.5\u00c2\u00b0C. What is the heat of fusion of mercury in J\/kg?<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To find the <strong>heat of fusion of mercury<\/strong>, we will apply the <strong>principle of conservation of energy<\/strong>. The heat lost by the water and the aluminum calorimeter must equal the heat gained by the mercury as it melts and warms up.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Given Data:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Specific heat of liquid mercury: cHg=140\u2009J\/kg\u2218Cc_{\\text{Hg}} = 140 \\, \\text{J\/kg}^\\circ\\text{C}cHg\u200b=140J\/kg\u2218C<\/li>\n\n\n\n<li>Mass of solid mercury: mHg=1.0\u2009kgm_{\\text{Hg}} = 1.0 \\, \\text{kg}mHg\u200b=1.0kg<\/li>\n\n\n\n<li>Initial temperature of mercury: THg,\u00a0initial=\u221239\u2218CT_{\\text{Hg, initial}} = -39^\\circ\\text{C}THg,\u00a0initial\u200b=\u221239\u2218C<\/li>\n\n\n\n<li>Final temperature: Tf=16.5\u2218CT_f = 16.5^\\circ\\text{C}Tf\u200b=16.5\u2218C<\/li>\n\n\n\n<li>Mass of aluminum calorimeter: mAl=0.50\u2009kgm_{\\text{Al}} = 0.50 \\, \\text{kg}mAl\u200b=0.50kg<\/li>\n\n\n\n<li>Specific heat of aluminum: cAl=900\u2009J\/kg\u2218Cc_{\\text{Al}} = 900 \\, \\text{J\/kg}^\\circ\\text{C}cAl\u200b=900J\/kg\u2218C<\/li>\n\n\n\n<li>Mass of water: mH2O=1.2\u2009kgm_{\\text{H2O}} = 1.2 \\, \\text{kg}mH2O\u200b=1.2kg<\/li>\n\n\n\n<li>Specific heat of water: cH2O=4186\u2009J\/kg\u2218Cc_{\\text{H2O}} = 4186 \\, \\text{J\/kg}^\\circ\\text{C}cH2O\u200b=4186J\/kg\u2218C<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Calculate heat lost by water and calorimeter<\/h3>\n\n\n\n<p><strong>Water:<\/strong> Qwater=m\u22c5c\u22c5\u0394T=1.2\u22c54186\u22c5(20.0\u221216.5)=1.2\u22c54186\u22c53.5=17,581.2\u2009JQ_{\\text{water}} = m \\cdot c \\cdot \\Delta T = 1.2 \\cdot 4186 \\cdot (20.0 &#8211; 16.5) = 1.2 \\cdot 4186 \\cdot 3.5 = 17,581.2 \\, \\text{J}Qwater\u200b=m\u22c5c\u22c5\u0394T=1.2\u22c54186\u22c5(20.0\u221216.5)=1.2\u22c54186\u22c53.5=17,581.2J<\/p>\n\n\n\n<p><strong>Aluminum calorimeter:<\/strong> QAl=0.50\u22c5900\u22c5(20.0\u221216.5)=0.50\u22c5900\u22c53.5=1,575\u2009JQ_{\\text{Al}} = 0.50 \\cdot 900 \\cdot (20.0 &#8211; 16.5) = 0.50 \\cdot 900 \\cdot 3.5 = 1,575 \\, \\text{J}QAl\u200b=0.50\u22c5900\u22c5(20.0\u221216.5)=0.50\u22c5900\u22c53.5=1,575J<\/p>\n\n\n\n<p><strong>Total heat lost:<\/strong> Qlost=17,581.2+1,575=19,156.2\u2009JQ_{\\text{lost}} = 17,581.2 + 1,575 = 19,156.2 \\, \\text{J}Qlost\u200b=17,581.2+1,575=19,156.2J<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Heat gained by mercury<\/h3>\n\n\n\n<p>Mercury must:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Melt (requires latent heat of fusion LfL_fLf\u200b)<\/li>\n\n\n\n<li>Warm from \u221239\u2218C-39^\\circ\\text{C}\u221239\u2218C to 16.5\u2218C16.5^\\circ\\text{C}16.5\u2218C<\/li>\n<\/ol>\n\n\n\n<p>Let LfL_fLf\u200b be the unknown heat of fusion in J\/kg.<\/p>\n\n\n\n<p><strong>Melting mercury:<\/strong> Qmelt=Lf\u22c51.0Q_{\\text{melt}} = L_f \\cdot 1.0Qmelt\u200b=Lf\u200b\u22c51.0<\/p>\n\n\n\n<p><strong>Heating mercury:<\/strong> Qwarm=1.0\u22c5140\u22c5(16.5\u2212(\u221239))=1.0\u22c5140\u22c555.5=7,770\u2009JQ_{\\text{warm}} = 1.0 \\cdot 140 \\cdot (16.5 &#8211; (-39)) = 1.0 \\cdot 140 \\cdot 55.5 = 7,770 \\, \\text{J}Qwarm\u200b=1.0\u22c5140\u22c5(16.5\u2212(\u221239))=1.0\u22c5140\u22c555.5=7,770J<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Set up energy balance<\/h3>\n\n\n\n<p>Qmelt+Qwarm=QlostQ_{\\text{melt}} + Q_{\\text{warm}} = Q_{\\text{lost}}Qmelt\u200b+Qwarm\u200b=Qlost\u200b Lf+7,770=19,156.2L_f + 7,770 = 19,156.2Lf\u200b+7,770=19,156.2 Lf=19,156.2\u22127,770=11,386.2\u2009J\/kgL_f = 19,156.2 &#8211; 7,770 = 11,386.2 \\, \\text{J\/kg}Lf\u200b=19,156.2\u22127,770=11,386.2J\/kg<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Final Answer:<\/h3>\n\n\n\n<p>Lf=11,\u2009\u2063386\u2009J\/kg\\boxed{L_f = 11,\\!386 \\, \\text{J\/kg}}Lf\u200b=11,386J\/kg\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation <\/h3>\n\n\n\n<p>This problem revolves around the principle of conservation of energy. When solid mercury is placed into a calorimeter containing water, the system reaches a thermal equilibrium. The initial temperatures are different. The mercury is at its melting point of \u221239\u2218C-39^\\circ\\text{C}\u221239\u2218C, while the water and aluminum calorimeter are at 20.0\u2218C20.0^\\circ\\text{C}20.0\u2218C. As the system reaches equilibrium, heat flows from the warmer substances (water and aluminum) to the colder substance (mercury).<\/p>\n\n\n\n<p>The energy given up by the water and aluminum is used in two stages. First, it melts the mercury. Second, it warms the now-liquid mercury from \u221239\u2218C-39^\\circ\\text{C}\u221239\u2218C to the final temperature of 16.5\u2218C16.5^\\circ\\text{C}16.5\u2218C.<\/p>\n\n\n\n<p>To find the heat of fusion, we calculated the heat lost by the water and the aluminum using the specific heat formula Q=mc\u0394TQ = mc\\Delta TQ=mc\u0394T. The total energy lost by the water and aluminum was about 19,156 joules. Then, we calculated how much energy is required to warm the mercury after melting, which came out to 7,770 joules.<\/p>\n\n\n\n<p>Since the total energy gained by the mercury must equal the total energy lost by the other components, we subtracted the energy used for warming from the total heat lost to isolate the energy used just for melting. This difference gives us the latent heat of fusion for 1 kilogram of mercury, which came out to be approximately 11,386 joules per kilogram.<\/p>\n\n\n\n<p>This value represents the energy required to convert solid mercury at its melting point into liquid mercury without changing its temperature.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"1024\" src=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-244.jpeg\" alt=\"\" class=\"wp-image-39243\" srcset=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-244.jpeg 1024w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-244-300x300.jpeg 300w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-244-150x150.jpeg 150w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-244-768x768.jpeg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>The specific heat of liquid mercury is 140 J\/kg\u00c2\u00b0C. When 1.0 kg of solid mercury at its melting point of -39\u00c2\u00b0C is placed in a 0.50-kg aluminum calorimeter filled with 1.2 kg of water at 20.0\u00c2\u00b0C, the mercury melts and the final temperature of the combination is found to be 16.5\u00c2\u00b0C. What is the heat [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-39242","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39242","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=39242"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39242\/revisions"}],"predecessor-version":[{"id":39244,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39242\/revisions\/39244"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=39242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=39242"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=39242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}