A petrol engine absorbs 2500 J of heat at 250$\degree$C and expels 2000 J at a temperature of 50$\degree$C. The magnitude of the change in entropy (in J/K) for the system is:

Question

Quizplus · Accepted Answer

The change in entropy is given by the formula:$$\Delta S = \frac{Q}{T}$$where Q is the heat absorbed or expelled and T is the temperature in Kelvin.In this case, the heat absorbed is 2500 J and the temperature is 250$\degree$C, which is 523 K. The heat expelled is 2000 J and the temperature is 50$\degree$C, which is 323 K.Therefore, the change in entropy is:$$\Delta S = \frac{2500 J}{523 K} - \frac{2000 J}{323 K} = 6.2 J/K$$So the correct answer is A) 6.2.

A Petrol Engine Absorbs 2500 J of Heat at 250 °\degree°

A Petrol Engine Absorbs 2500 J of Heat at 250 $\degree$