Question 970: Thermodynamics & KTG

Question

When 1 kg of ice at 0
o
C melts to water at 0
o
C,  the resulting change in its entropy, taking latent heat of ice to be 80 cal/
o
C, is

Accepted Answer

Change in entropy is given by
$$dS = {{dQ} \over T} \Rightarrow \Delta S = {{\Delta Q} \over T} = {{m{L_f}} \over {273}}$$
$$\Delta S = {{1000 	imes 80} \over {273}} = 293\,cal/K$$
Note :
In the question paper unit of latent heat of ice is given to be cal/ÃÂ°C. It is wrong. The unit of latent heat of ice is cal/g.

Answer

273 cal/K

Answer

8 $$ 	imes $$ 10
4
cal/K

Answer

80 cal/K

Answer

293 cal/K

Thermodynamics & KTG

When 1 kg of ice at 0 o C melts to water at 0 o C, the resulting change in its entropy, taking latent heat of ice to be 80 cal/ o C, is

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