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(a) What is meant by specific latent heat of fusion of a substance? (1mark)
The amount of heat energy required to change a unit mass of solid to liquid at constant temperature.
(b) (i) mass of condensed steam. (1mk)
Mass of steam = 156 - 145 = 11 g
(ii) Heat gained by water + heat gained by calorimeter = 0.085 x 4200 (48-20) + 0.06 X 390(48-20)
= 10,651.2 J
(iii) Heat lost by steam=Heat lost by condensing steam + heat lost by condensed steam
= 0.011 X Lv+ 0.011 X 4200 X (100 – 48)
= 0.011Lv+ 2,402.4
(iv) Heat lost by steam+heat lost by condensed water = heat gained by water + heat gained by calorimeter
0.011 XLv+ 0.011 X 4200 X (100 – 48) = 0.085 X 4200 (48-20) + 0.06 X 390(48-20)
Lv= 749,890.9091JKg-1
(v) There are no heat losses
There is no change in mass
john3 answered the question on November 2, 2017 at 21:06
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