Answer
$\Delta E = -77 J$
Exothermic
Work Step by Step
From Section 5.2: $\Delta E = q + w$
We have q = 0.763 kJ and w = -840 J. First we convert the 0.763 kJ to Joules by multiplying by 1000 since there are 1000J in one kJ and we have 763 J.
Then we add the two and have
$\Delta E = 763J + (-840J) = -77 J$
From table 5.1, since it is negative, energy is lost from the system, which means energy flows out so it is exothermic
