How much work is done on the gas in the following process A

How much work is done on the gas in the following process? A 2000 cm^3 container holds 0.1 mol of helium gas at 300 degree C. How much work must be done to compress the gas to 1000 cm^3 at Constant pressure Constant temperature A rapidly spinning paddle wheel raises the temperature of 200 mL of water from 21 degree C to 25 degree C. How much heat is transferred and Work is done in this process? 100 J of heat energy are transferred to 20 g of mercury by how much does the temperature increases? How much heat is needed to raise the temperature of 20 g of water by the same amount?

Solution

1(a). Work done = Area under curve and volume axis

                        = area of the triangle + area of the rectangle under cap

                        =[(1/2)(300-100)cm ³ (400-200)kPa ] +[200 kPa x (300-100)cm ³]

                        = [0.5 x200 cm ³ x 200 kPa ]+[200 kPa x 200 cm ³]

                        = 300 cm ³ x200 kPa

                       = 300 (10^-2 m) ³ x 200x10 ³ Pa

                       = 300 x10 ^-6 x200 x10 ³

                       = 60 J

1(b).Work done = area under line and volume axis

                       = 400 kPa x (300-100)cm 3

                       = 400 x10 ³ Pa x200 x10 ^-6 m ³

                       = 80 J