Latent heat of fusion of ice

Latent heat of fusion (L) is the heat per unit mass required to convert a solid into a liquid at it melting point.
Formula L = Q/m
L is measured in J/g or J/kg
This video describes a simple experiment that allows to estimate the latent heat of fusion of ice.
Ice close to its melting point of 0 degrees Celsius is mixed with water at room temperature. (This is often done to cool drinks). By measuring the final temperature of the mixture, the latent heat L can be calculated.
The calculations are based on the assumption that the heat lost by the water in the cup is gained by ice which first melts and then the resulting water at 0 degrees Celsius warms up until it reaches thermal equilibrium with the water which was initially in the cup. In reality, the ice takes in heat not only from the existing water but also from the surroundings (the room temperature was around 23 degrees C). Also, it is possible that the ice was at a couple of degrees below zero. All in all, this method is not extremely accurate and it is based on some optimistic assumptions but, nevertheless, it provides the correct order of magnitude for the latent heat.
The accepted value of the latent heat of fusion of ice is 334 J/g or 3.34 x 10^5 J/kg

[@thatonetommyguy1215]

Hey IBPhysicsHelp! This is Tommy, from your class a few years ago. just wanted to say that I'm glad to see you're still uploading, and I hope everything is going well in Hamburg.

[@ibphysicshelp]

Hi Tommy. Good to hear from you! Leaving aside the pandemic and the war, thing are fine in HH :). I hope the Uni is going well.

[@afakethrum]

- 🧊 Latent heat of fusion defines heat needed to convert between solid and liquid states. - 🌡 Ice temperature is approximately zero degrees Celsius for the experiment. - ⚖ Heat exchange is assumed only between ice cube and water inside the cup. - 📊 Calculated latent heat of fusion: 300 joules per gram. - 📋 Experimental setup includes a balance, styrofoam cup, thermometer, ice, and water. - 🔄 Thermal equilibrium is established between thermometer and water for accurate temperature measurement. - 🔄 Lid on cup minimizes heat exchange with surroundings during experiment. - 📚 Literature value for latent heat of fusion of ice: approximately 334 joules per gram. Created by Harpa AI

[@mblphysics3735]

Buna ziua, frumos video! M-am gandit ca daca nu presupunem ca gheata e la 0 grade C putem imbunatati rezultatul final. Am facut calculul invers, pornind de la L este 334 J/g (3430 J pentru topirea ghetii) si am obtinut o temperatura initiala a ghetii de +16 grade C. Desigur, speram sa obtin ceva in jur de cateva grade "frig" :). Ma intreb de unde provine eroarea.

[@ibphysicshelp]

Bună. Căldura pierdută de apă la răcire e de 3780 J. Cu valoarea acceptată pentru L e nevoie de 3430 J pentru topirea gheții, după cum spuneți. Apa provenită din gheață mai ia 691 J pentru a se încălzi la temperatura finală de echilibru. In total, căldura absorbită de gheață e de 4121 J. (Deci mai mult decât pierde apa aflată inițial în pahar! - ceea ce desigur, nu ar trebui să se întîmplă). Eu cred că aici factorul determinant e căldura absorbită de sistem din împrejurimi. Cu alte cuvinte, estimarea că gheata ar fi primit doar 3780 J de la apa existentă în pahar e o subestimare semnificativă. Desigur, e posibil ca și gheata folosită să fie in jur de -2 grade. In acest caz, caldura necesară pentru a o încălzi la 0 e doar de aproximativ 43 J.

[@sibusisomgidi9684]

What is specific heat of calorimeter?

[@ibphysicshelp]

It usually refers to the specific heat of a container in which an heat exchange occurs. A calorimeter is a well insulated container. Let’s assume that you have a plastic cup (the “calorimeter”) and some water in it. Now let’s pour some hot water to make some lukewarm water. To find the final temperature of the mixture Ordinarily, you would consider only the heat exchange between cold and hot water (Q lost by hot = Q gained by cold). When the specific heat of the container is given a better equation would be Q lost by hot water = Q gained by cold water + Q gained by container. Or, in simple words, specific heat of a calorimeter is the specific heat of the material from which the cup is made of.