Question

Minta tolong bantuin kimia dong:)

Answer 1

1. endoterm : trjdi pnyerapan kalor dri lingkungan, delta H positif krn Hakhir > Hawal, suhu sistem naik akibat reaksi (sstem jd pnas), lingkungan jd dingin.
eksoterm : trjd plepasan kalor ke lingkungan, deltaH negatif krn Hakhir < Hawal, suhu sistem turun akbat reaksi (sstem jd dingin), lingkungan jd panas

Answer 2

4. Zn + S → ZnS               ΔH = - 206 kJ
   ZnS + 2 O2 → ZnSO4   ΔH = - 777 kJ
hasil: Zn + S + 2 O2 → ZnSO4  ΔH = - 983 kJ

5. C2H5OH + 3 O2 → 2 CO2 + 3 H2O
ΔH = [(2 × ΔH CO2) + (3 × ΔH H2O)] - [ΔH C2H5OH - (3 × ΔH O2)]
     = [(2 × - 393,5) + (3 × - 285,85)] - [- 278 + (3 × 0)]
     = - 1366,55 kJ/mol

6. CH4 + 2 O2 → CO2 + 2 H2O
ΔH = [(4 × C-H) + (2 × O=O)] - [(2 × C=O) + (4 × H-O)]
     = [(4 × 413) + (2 × 495)] - [(2 × 799) + (4 × 463)]
     = - 808 kJ/mol