Answer: 2.292 kJ

500 $cm^3$ of 0.1 M HCl = $\frac{500 \times 0.1}{1000}$ = 0.05 mol

200 $cm^3$ of 0.2 M NaOH = $\frac{200 \times 0.2}{1000}$ = 0.04 mol

$\therefore$ 0.04 moles of NaOH is neutralised by 0.04 mol of HCl.

$\therefore$ Heat released = $57.3 \times 0.04 = 2.292$ kJ