Question

Calculate the work engergy gained or lost by the system when a gas expands from 35 to 55 l against a constant external presure of 3atm.

Answer 1

Answer:  The work energy lost by the system is -6078 Joules

Explanation:

According to first law of thermodynamics:

$\Delta E=q+w$

$\Delta E$=Change in internal energy

q = heat absorbed or released

w = work done or by the system

w = work done by the system=$-P\Delta V$  {Work is done by the system as the final volume is greater than initial volume and is negative}

where P = pressure = 3 atm

$\Delta V$ = change in volume = (55-35) L = 20 L

w =$-3atm\times (20)L=-60Latm=-6078Joules$  

{1Latm=101.3J}

Thus work energy lost by the system is -6078 Joules