tolong dibantu yang di fto itu kakak kakak

DH = entalpi reaktan - entalpi produk
DH = (4(C-H) + Cl-Cl) - (3(C-H) + C-Cl + H-Cl)
-23.9 = 4(C-H) + 58 - (3(C-H) + 78 + 103)
-23.9 = 4(C-H) + 58 - 3(C-H) - 78 - 103
-23.9 = (C-H) -123
C-H = -23.9 + 123
= 99.1 kkal/mol