One mole of a gas expands by 3L against a constant pressure of 3 atmosphere. Calculate the work done in :
(a) L. atmosphere (b) Joules
(c) Calories

Answer

(a) W= - 9.0 L atm ( b) W= - 911. 7 J ( c) W= - 217 .9 cal

Explanation

Given : Number of the moles of a gas = n= 1 mol
volume of expansion = `Delta V = 3 L`
Constant pressure `=P _(ex) =3 atm`
Work (w) = ? in L atm , Joules and Calories
`(a) W =- P_(ex) xx Delta V`
`=- 3xx 3`
=- 9.0 L atm
(b) :' 1 L atm = 101 .3 J
`:' W =- 90 xx 101 .3 J`
=- 911.7 J
(c ) :' 4.184 J = 1 cal
`:' W = (-911.7)/(4.184)`
=-217. 9 cal