Study the following thermochemical equations:<br><br><br>The correct order of enthalpies of formatio — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Reaction 1 tells us $H_B - H_A = 100 \implies H_B > H_A$. Reaction 2 tells us $H_C - H_B = -80 \implies H_B > H_C$. Adding both tells us $H_C - H_A = 20 \implies H_C > H_A$. Ordering them: $H_A < H_C < H_B$.