Conversion of water into steam is a?
Correct answer: A. Spontaneous reaction
- A. Spontaneous reaction
- B. Exothermic Reaction
- C. Reversible Reaction
- D. Combustion Reaction
Explanation
OPTION A: Because ∆G =∆H - T∆S at this temperature ∆G = 0, indicating that the liquid and vapor phases are in equilibrium. The normal boiling point of water is therefore 373.15K. Above the normal boiling point, the T∆S term is greater than ∆H, making ∆G < 0; hence, liquid water evaporates spontaneously.OPTION B: Conversion of water into steam is not an exothermic reaction, but an endothermic process as it absorbs heat to convert it from liquid to gas state.OPTION C: The conversion of water into steam is not a reversible reaction because it involves a change in the physical state of matter, which is not a reversible process.OPTION D: It is not a combustion reaction because it is a physical change caused by the application of heat, not a chemical reaction involving fuel and an oxidizing agent.
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About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
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