Latent Heat

  1. Diagram 5.1(a) is an experimental set-up and 5.1(b) is a control set-up. When the power supply is switch on, water will drips out of the filter funnels. As soon as water is dripping out at a constant rate, beaker A and beaker B are placed under the filter funnels and a stop watch is started simultaneously.

Rajah 5.1(a) ialah radas eksperimen dan rajah 5.1(b) ialah radas kawalan. Apabila bekalan kuasa dihidupkan air akan menitis dari corong turas. Sejurus titisan air menitis pada kadar seragam, bikar A dan bikar B  diletakkan di bawah corong turas dan jam randik dimulakan serentak.









(a)              What is the purpose of having a a control set-up?          

            Apakah tujuan radas kawalan?
                       
                        ………………………………………………………………………….
[1 mark] / [1 markah]

 After 5 minutes, the mass of water collected in beaker A and B are measured. Table 5.1 below shows the data collected from the experiment.
            Selepas 5 minit, jisim air yang dikumpulkan dalam bikar A dan B disukat. Jadual 5.1 di bawah menunjukkan data yang diperolehi dari eksperimen tersebut.
           
Mass of water collected in beaker A, / g
Jisim air yang dikumpulkan dalam bikar A, / g
180
Mass of water collected in beaker B, / g
Jisim air yang dikumpulkan dalam bikar B, / g
12
Amount of heat supplied, Q / kJ
Jumlah haba dibekalkan, Q /  kJ
56.8
Table 5.1 / Jadual 5.1

(b)               What is the mass of ice melted by the energy supplied by the power supply?
            Berapakah jisim ais yang dileburkan oleh tenaga dibekal oleh bekalan kuasa?
                       
…………………………………………………………………………..
[1 mark] / [1 markah]


(c)                                        Name the heat energy required to melt the ice in this experiment.
            Namakan tenaga haba yang diperlukan untuk melebur ais dalam eksperimen ini.
                       
………………………………………………………………………….
[1 mark] / [1 markah]


(d)                                       Calculate the heat energy in (c) that is specific for one kg of ice.
            Hitung tenaga haba di (c) yang tertentu untuk satu kg ais.




[3 marks] / [3 markah]

(e)                Value calculated in (d) is higher than the actual value. Explain why?                        
            Nilai yang di hitung di (d) lebih tinggi dari nilai sebenar. Terangkan mengapa?
                       
                        …………………………………………………………………………..
[1 marks] / [1 markah]

(f)                                          Suggest one way to get a more accurate value.
             Cadangkan satu kaedah untuk mendapat nilai yang lebih jitu.
                         ………………………………………………………………………….
[1 mark ] / [1 markah]








Measure mass of ice melted by heat from surrounding

168 g
Latent Heat
L = H/m

=  56800/0.168
=  338 095 Jkg-1
Heat loss to surrounding
Wrap filter funnel with wool.