A gas at a pressure of 1 atm is compressed at a constant pressure from 10.0 litres to 2.0 litres. If 500 J of heat energy leaves the gas calculate (i) the work done by the gas and (ii) the change in its internal energy.

A gas at a pressure of 1 atm is compressed at a constant pressure from

1.	A gas at a pressure of 1 atm is compressed at a constant pressure from 10.0 litres to 2.0 litres. If 500 J of heat energy leaves the gas calculate (i) the work done by the gas and (ii) the change in its internal energy.
Answer» Solution :`P = 1 ATM = 101325 N//m ^(2)` `Delta V = (2-10) =- 8` litres `=0 8 xx 10 ^(-3) m ^(3)` Work DONE `= Delta W = P Delta V` `= 101325 xx (-8 xx 10 ^(-3))` `=- 826J` Heat LEAVING the gas `= Delta Q =- 500 J` Changle in internal energy `= Delta U =?` `Delta U = Delta Q - Delta W` `=- 500 + 826` `= 326 J`