The industrial manufacture of ethanol is primarily achieved via two distinct synthetic pathways, as represented by the equations below:
Reaction A (Catalytic Hydration):
C2H4(g)+H2O(g)→C2H5OH(g) \text{C}_2\text{H}_4\text{(g)} + \text{H}_2\text{O(g)} \to \text{C}_2\text{H}_5\text{OH(g)} C2H4(g)+H2O(g)→C2H5OH(g)Reaction B (Anaerobic Fermentation):
C6H12O6(aq)→2C2H5OH(aq)+2CO2(g) \text{C}_6\text{H}_{12}\text{O}_6\text{(aq)} \to 2\text{C}_2\text{H}_5\text{OH(aq)} + 2\text{CO}_2\text{(g)} C6H12O6(aq)→2C2H5OH(aq)+2CO2(g)Identify one specific agricultural crop grown on a large scale to provide the starch or sugar source required for Reaction B.
State the name or formula of the catalyst employed in Reaction A, and specify the typical operating temperature (including units) used to maintain an acceptable rate and yield in this industrial process.
Explain why the reaction vessel for Reaction B must be carefully sealed to exclude atmospheric oxygen during the fermentation process.
A biotechnology firm is planning to establish a major ethanol production plant in a rural region of Brazil. This region possesses extensive arable land dedicated to agriculture but lacks any local petrochemical infrastructure or oil refineries.
Suggest three distinct reasons why the firm should opt for Reaction B rather than Reaction A for this specific plant.
In a school laboratory, ethanol can be converted back into ethene.
Write a balanced chemical equation for this transformation and state the chemical role of the concentrated acid catalyst used to facilitate this reaction.