Answer:
1. C)
2. B)
3. D)
4. A)
Explanation:
Enthalpy change is the heat of the reaction measured at constant pressure.
i.e. [tex]q_{p}=\Delta H[/tex]
Chemical reactions are accompanied either by the absorption of heat (endothermic) or by the release of heat (exothermic)
1) 1 mol NaCl (s) ↔ 1 mol NaCl(l)
Ans: C) Molar heat of fusion; endothermic
Molar heat or enthalpy of fusion is the amount of energy absorbed when a solid melts into a liquid. It is an endothermic process since heat is absorbed.
2. C4H10 O(l) ↔ C4H10O (g)
Ans: B) Molar heat of vaporization; endothermic
Molar heat or enthalpy of vaporization is the amount of energy absorbed when a liquid evaporates into a gas. It is an endothermic process since heat is absorbed.
3. H2O(g) ↔ H2O (l)
Ans: D Molar heat of condensation; exothermic
Molar heat or enthalpy of condensation is the amount of energy released when a gas condenses into a liquid. It is an exothermic process since heat is released.
4. 1 mol NaCl(s) + 3.88 kJ/mol ↔ 1 mol NaCl(aq)
Ans: A) Molar heat of solution; endothermic
Heat of solution is the amount of heat absorbed when 1 mole of a substance is dissolved in water.
