The amount of work done by a gas which is being isobarically heated from 27° C to 127° C in a vessel closed by a movable piston with a cross-sectional area of 20 cm 2 and weighing 5 kg in the following two cases is: (1) w1, when the vessel is arranged horizontally (Figure a), and (2) w2, when the vessel is arranged vertically (Figure b). If the initial volume of the gas is 6 litres, then find (w1+w2) in joule. Assume standard atmospheric pressure =100 kPa and neglect friction.

Question

The amount of work done by a gas which is being isobarically heated from 27° C to 127° C in a vessel closed by a movable piston with a cross-sectional area of 20 cm 2 and weighing 5 kg in the following two cases is: (1) w1, when the vessel is arranged horizontally (Figure a), and (2) w2, when the vessel is arranged vertically (Figure b). If the initial volume of the gas is 6 litres, then find (w1+w2) in joule. Assume standard atmospheric pressure =100 kPa and neglect friction. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

P V =n R T P V =n R × 300 P V prime =n R × 400 (V prime/V) =(4/3) V prime =8 text litres w1 =P0 Δ V =105 ×[8-6] × 10-3=200 J P2 =P0+(m g/A)=105+(5 × 10/20 × 10-4) =105+2.5 × 104 w2 =12.5 × 104 ×[8-6] × 10-3=250 J w1 +w2=450 J

PV=nRT PV=nR×300 PV′=nR×400 VV′​=34​ V′=8 litres w1​=P0​ΔV =105×[8−6]×10−3=200J P2​=P0​+Amg​=105+20×10−45×10​ =105+2.5×104 w2​=12.5×104×[8−6]×10−3=250J w1​+w2​=450J