If ∆H is negative, the reaction is...

If ∆H is negative, the reaction is...

• A. Endothermic
• B. Exothermic
• C. Equilibrium favored
• D. Cannot be determined

Answer: (B)

Enthalpy change tells us whether heat is released or absorbed during a reaction at constant pressure. If ΔH is negative, the system loses heat to the surroundings, which means the reaction is exothermic. In an exothermic process, energy is given off as heat, often making the surroundings feel warmer. The opposite, endothermic, has a positive ΔH because heat is absorbed from the surroundings. The sign of ΔH alone doesn’t determine equilibrium; it only describes heat flow.

Enthalpy change tells us whether heat is released or absorbed during a reaction at constant pressure. If ΔH is negative, the system loses heat to the surroundings, which means the reaction is exothermic. In an exothermic process, energy is given off as heat, often making the surroundings feel warmer. The opposite, endothermic, has a positive ΔH because heat is absorbed from the surroundings. The sign of ΔH alone doesn’t determine equilibrium; it only describes heat flow.