Answer
489 J
Work Step by Step
Internal energy, ∆U= q+w= $q - p_{ex}∆V$
where q is the heat absorbed, $p_{ex}$ is the external pressure and ∆V is the change in volume.
Given, q= 565 J , ∆V=(0.85-0.10)L = 0.75 L
and $p_{ex}$= 1.0 atm
Then, ∆U= 565 J-0.75 L.atm
As 1.00 L.atm= 101.33 J, 0.75 L.atm = (0.75×101.33)J $\approx$76 J
Now, ∆U= 565 J- 76 J = 489 J
