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Question #44220
The Question
Consider the acid-catalyzed esterification of octadecanoic acid with octan-1-ol to form octyl octadecanoate and water. At , the standard enthalpy and entropy of the reaction producing liquid water are and , respectively.
The standard enthalpy of vaporization of water is and its standard entropy of vaporization is .
The reaction is carried out at in a continuous flow reactor. Due to the high boiling points of the organic species, they remain entirely in the liquid phase, but water is formed exclusively in the vapor phase. Assuming all standard enthalpies and entropies are independent of temperature, what is the value of for this specific equilibrium at ?
( is the universal gas constant in )
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Mechanism_Trap
Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.
Concepts Behind This Question
Acid-Catalyzed Hydration Mechanism|Esterification Reversibility|First Law Consistency
Why This Question Is Tricky
Common Mistakes
This problem tests the 'Water Activity Under First Law Constraints' trap.
Students frequently calculate high-temperature equilibrium constants by blindly plugging standard table values (which assume liquid water as the product) into the Gibbs free energy equation, yielding Option B (20/R).
By using heavy organic molecules (octadecanoic acid and octan-1-ol), the liquid state of the organics is realistically maintained at 400 K, making the vaporization of water the sole, critical thermodynamic correction required.
Failing to account for the heat of vaporization and entropy of vaporization of water violates the First and Second Laws of Thermodynamics for the actual reaction coordinate.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Thermodynamics - Class 11 Part 1 |
| Concept | First Law Consistency |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |