In the equilibrium H2O(l) ⇌ H2O(g) ΔH = +41 kJmol-1, what is the sign of ΔH for the forward direction?

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Multiple Choice

In the equilibrium H2O(l) ⇌ H2O(g) ΔH = +41 kJmol-1, what is the sign of ΔH for the forward direction?

Explanation:
Vaporizing water is an endothermic process: it requires heat to break intermolecular forces as liquid becomes gas. The enthalpy change for this forward direction is given as +41 kJ/mol, so heat is absorbed per mole. A reverse process would release that amount of energy (negative sign). Therefore, the sign for the forward direction is positive.

Vaporizing water is an endothermic process: it requires heat to break intermolecular forces as liquid becomes gas. The enthalpy change for this forward direction is given as +41 kJ/mol, so heat is absorbed per mole. A reverse process would release that amount of energy (negative sign). Therefore, the sign for the forward direction is positive.

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