Ten moles of a monatomic ideal gas initially has a volume of 0.800 m3 . The gas undergoes four processes: (1) Without changing its temperature, the gas expands to a volume of 1.200 m3 , at which point its pressure is 20.00 kPa. (2) The gas expands to a volume of 1.480 m3 without heat entering or leaving the gas. (3) Without changing its temperature, the gas is compressed until its pressure is 21.15 kPa. (4) The gas is compressed to a pressure of 30.00 kPa without heat entering or leaving the gas.

 i) Calculate the work done by the gas in processes (1) and (3). 

 ii) Determine the process that the gas undergoes. 

 iii) Using the definition of the entropy, calculate the total change in entropy during the four processes. Comment on your answer.