During an isothermal process one mole of a monoatomic gas did 3000 J of work on its surrounding. The final volume and pressure of the gas are 25 L and 1 atm, respectively. What was the initial volume of the gas

 The initial volume of the gas is 7.72 L

Explanation:

For an isothermal process the temperature is constant.  

as P = pressure = 1 atm ,

V = Volume =  25 L

n = moles

R= gas constant

T = temperature

    (1Latm=101.3 J)

For isothermal reaction :

where , w = work done by  system = -ve

n = moles = 1

= final volume = 25 L

= initial volume = ?

Thus initial volume of the gas is 7.72 L

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.