Measuring the specific latent heat of merger of H2O ( ice ) :
In our day-to-day lives, heat can be found in everyplace. Cooking nutrient heat is needed, it besides makes people experience warm and bring forth more energy. Therefore to cognize the specific latent heat of merger of H2O, both we need to cognize procedure of the heat was transferred and kinetic energy.The purpose of this experiment was to happen out the specific latent heat of merger of H2O and steam. First of all, heat is a sort of energy, which transfers from one object to another because of their different temperatures. The SI unit of the specific latent heat is joule per kg ( J kg-1 ) . The specific latent heat of merger which is the unit used to cipher the energy demand to alter unit mass of a substance from a solid into a liquid without in temperature. The equation Q=ItV=ML was used to cipher the energy needed from solid to liquid. Where Q is the heat supplied ; m is the mass of the solid, L stands for the specific latent heat of merger. However, in this procedure, foremost to be calculated the energy supplied to the warmer and divided it by the mass of ice melted by the warmer to happen the specific latent heat of merger of ice. Next is the specific latent heat of vaporisation, which was used to cipher how much heat energy for a substance demand to alter units of mass from liquid into vapor without in temperature. It besides defined as the equation is Q=m fifty-five +h “where lv represents the specific latent heat of vaporisation of the liquid and H is the heat lost from the ‘jacket ‘ in clip t” . Duncan ( 2000: 69 ) .
Finally, calorimeter is merely a sort of equipment which uses to mensurate heat. There are some equations were use in the consequence computation. The basic theory of the simple experiment is as above.MethodsPart.1 the specific latent heat of merger of iceThe equipment of this experiment was two funnels and two barrels, an ammeter and a voltmeter supplied. First, two funnels were filled with crushed ice, and so the warmer was put in one of the funnels and left them both for five proceedingss.
During these, the warmer reached the temperature of the ice in order to alter the ice to H2O rapidly. Following, while turned on the warmer, the value of electromotive force and current were recorded. After entering the values, the mass of H2O was measured that caught from each funnel in five proceedingss. Finally, after acquiring the values of multitudes, electromotive force and current, the computation was done.Figure 1, more ice thaws in the side with the beaterPart.2 the specific latent heat of vaporisation of waterFinding lv can be done utilizing the equipment below in figure 2. First of all, put a measurement cylinder on a top pan balance and environ the cylinder with dawdling. The inside aluminum metal container was measured by electronic balance and the lid support unfastened. After the mensurating cylinder was filled with H2O, the power was turned on to provide. Then wait the minutes until the H2O came back to the furuncle. After the H2O was boiling, the mass of H2O was recorded and the clock was started. Third, the power supply was connected and the power was set to 1100w. Finally, a small of the H2O in cylinder was emptied to go steam and the mass of H2O besides was recorded. The setup in this experiment as in figure 2.Figure 2, the boiling H2O in mensurating cylinderResultsPart 1.
The specific latent heat of merger of ice.Table.1 The measuring of latent heat of merger of ice.The ice with heaterFunnel without heaterMass of cup ( g ) 7373Mass of cup with H2O ( g ) 9383Mass of H2O ( g ) 2010Table.1 shows the measuring of latent heat of merger of ice. The multitudes are measured by electronic balance ; the current of the circuit is 1.5A and the electromotive force of the circuit is 6V.The mistake of mass: ± 1gThe mistake of heat: ± 10JPart.2 the specific latent heat of vaporisation of water.M1 ( the boiling H2O ) M2 ( after 3 proceedingss ) 100049Table.2 The information of the specific latent heat of vaporisation of water.Table.2 shows the information of the specific latent heat of vaporisation of H2O which is the difference of the multitudes of H2O. In the experiment, the mass of the balance is 79g ; the temperature of the H2O is 100? ; the power of cylinder is 1100W ; the clip is 3 proceedingss. And the mistake of the mass is ± 1g.DiscussionThe specific latent heat of merger of ice and the specific latent heat of vaporisation of H2O are calculated by the measuring in the tabular arraies of consequence subdivision. The computation of the specific latent heat of merger of ice is as follows. Heat lost by H2O is equal to the mass times the specific latent heat of merger and the equation is VtI=ML, M is mass of H2O in difference, t bases for the clip taken for heat the ice and L is the latent heat of merger of ice. ThereforeL ==?=2700J ?L=2.7?105Jkg-1 and it is non really similar to the exact value of the latent heat of merger of ice, which is 3.3?105 Jkg-1. Following portion is the specific latent heat of vaporisation of H2O. The heat gained to the H2O and the cylinder is equal to the work down by the circuit which is 1100W, E=W ? t=M lv, which E is the energy gained to the H2O and the cylinder, M is mass of balance, fifty-five represents the specific latent heat of vaporisation of H2O. From the equation merely above, hence Lv= = & gt ; and so Lv =2.5?106 Jkg-1.
It is besides non really similar to the exact value of the specific latent heat of vaporisation of H2O, which is 2.3?106 Jkg-1.According to Duncan ( 2000:68 ) “the kinetic theory sees the supply of latent heat to a runing solid as enabling the molecules to get the better of sufficiently the force between them for the regular crystalline construction of the solid to be broken down. And when vaporisation of a liquid occurs a big sum of energy is needed to divide the molecules and let them to travel about independently as gas molecules” .