What happens when ethanol reacts with at 443K?

Ethene

The correct answer is option 3. Ethene.

When ethanol \((CH_3CH_2OH)\) reacts at 443K (approximately 170°C), it undergoes a process called dehydration. This reaction removes a water molecule \((H_2O)\) from the ethanol molecule, resulting in the formation of ethene \((CH_2=CH_2)\).

Here is a breakdown of the reaction:

Heat as a Catalyst: The temperature of 443K provides the activation energy needed for the reaction to occur.

Dehydration Process: One of the hydrogen atoms from a hydroxyl group \((OH)\) on the ethanol molecule bonds with the oxygen atom in the same group. Simultaneously, a hydrogen atom from the adjacent carbon atom bonds with the oxygen atom to form a water molecule. This water molecule is then eliminated from the molecule.

Formation of Ethene: The remaining carbon chain forms a double bond between the two carbons that lost their hydrogen atoms, resulting in ethene, an alkene (hydrocarbon with a carbon-carbon double bond).

Therefore, the answer is Ethene \((CH_2=CH_2)\).

It is important to note that the reaction conditions can influence the products formed. In some cases, with the presence of an appropriate catalyst (like concentrated sulfuric acid), the reaction might favor the formation of diethyl ether \((CH_3CH_2OCH_2CH_3)\) through a different reaction pathway.