Answer
$\Delta E_{int}=1.99kJ$
Work Step by Step
From first law of thermodynamics;
$\Delta E_{int}=Q-W$
This can be rearranged as:
$W=Q-\Delta E_{int}$
We plug in the known values to obtain:
$\Delta E_{int}=6.98\times 10^3-4.99\times 10^3=1.99\times 10^3=1.99kJ$
