Which of the following is the most suitable requirement for the dehydration of ethanol to form an ether?
A. Sodium hydroxide at 443K
B. Sulphuric acid at 443K
C. Sulphuric acid at 413K
D. Sodium hydroxide at 413K
Answer (2)
The most suitable requirement for the dehydration of ethanol to form an ether is option B: Sulphuric acid at 443K. This choice provides the necessary acid catalyst and optimal temperature to drive the reaction efficiently. Other options either use unsuitable reagents or lower temperatures which could hinder the reaction process.
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To determine the most suitable condition for the dehydration of ethanol to form an ether, it's important to understand the chemical process involved.
The dehydration of ethanol (C₂H₅OH) can lead to two different products depending on the conditions used:
Ethene (C₂H₄): This forms on heating ethanol with concentrated sulfuric acid at temperatures around 443 K.
Diethyl ether (C₂H₅-O-C₂H₅): This forms under milder conditions, typically around 413 K, when ethanol is treated with sulfuric acid.
In this question, the goal is to form an ether, specifically diethyl ether. For this reaction, sulfuric acid at a lower temperature, such as 413 K, is used to promote the formation of diethyl ether rather than leading to ethene production.
Therefore, the correct choice is (C) Sulphuric acid at 413K.
Here's a brief step-by-step explanation of the reaction:
Reactants: Ethanol (C₂H₅OH) is mixed with a small amount of concentrated sulfuric acid.
Temperature Condition: The mixture is heated to about 413 K (or approximately 140°C).
Dehydration Reaction: Under these conditions, the alcohol groups react to form an ether. The sulfuric acid acts as a dehydrating agent by removing a water molecule from two ethanol molecules, linking them into an ether bond.
Product: The product of this reaction is diethyl ether, which is a functional compound used as a solvent and has historical significance in anesthesia.
This understanding of the conditions and reactions provides a foundation for recognizing how specific catalysts and temperatures can direct chemical reactions toward desired products.
