A + B → D + E ΔH₂ = -50 kJ D + E → C ΔH₃ = +30 kJ (reverse: -30)
Using Hess's law, what is ΔH₁ for A + B → C?
- A
+80 kJ
- Bcheck_circle
-20 kJ
- C
-80 kJ
- D
+20 kJ
Explanation
ΔH₁ = ΔH₂ + ΔH₃ = (-50) + (+30) = -20 kJ.
Hess's Law
AP Chemistry· difficulty 3/5
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