Question

n ideal gas is enclosed in a cylinder with a movable piston on top of it. The piston has a mass of 8,000 g and an area of 5.00 cm2 and is free to slide up and down, keeping the pressure of the gas constant. (a) How much work is done on the gas as the temperature of 0.180 mol of the gas is raised from 30.0°C to 325°C?

Answer 1

The mass of the piston is 8kg. And the area (A) of the piston is 5.00 cm² .

So, the gravitational force on the piston is

                                   Weight = 8 x 10 = 80 N

SO, the pressure (P) on the gas due to the piston is

                                   P = F/A = 80/(5 x 10^-4) =1.6 x 10⁵ pa

If the pressure remains constant, then the workdone can be calculated as

                                    W = P dV = P (V_f - V_i )

V_f is final volume, and V_i is initial volume.

We know the gas equation

                                       

We have,  

   and        

                 n = 0.180 mol

We can calculate V_i as

                                       

As n,P,R is constant, we can write

                                       

                                  or,

                                  or,

So, the work done on the gas is