Calculate the standard heat of reaction ( kJ):

C₂H₄ (g) + 2Cl₂(g) C₂HC_l3(l) + H₂(g) + HCl (g)

From

C₂H₄ (g) + 2Cl₂(g) C₂H₂Cl₄(l) + H₂(g) H_r^{^} = -400 kJ

C₂H₂Cl₄ (l) C₂HCl₃(l) + HCl (g) H_r^{^} = -60 kJ

Report your answer up to 2 decimal points.