Question

what is the change in internal energy when a gas contract from 377 ml to 177 ml under constant pressure of 1520 Torr while the same time be cooled by removing 124 joule heat

Answer 1

Answer: 40396J

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 on the system=$-P\Delta V$  {Work is done on the system as the final volume is lesser than initial volume and is positive}

P= pressure= 1520 torr=2 atm        (760 torr=1atm)

w = =$-2.0atm\times (177-377)L=400Latm=40520Joules$  {1Latm=101.3J}

q = -124J   {Heat released by the system is negative}

$\Delta E=40520+(-124)=40396J$