Answer :
Final answer:
The primary reason for excluding water in a Grignard reaction is to prevent the Grignard reagent from reacting with it, which would result in the loss of its reactivity and reduce the yield of the desired product. The correct option is B.
Explanation:
In a reaction involving a Grignard reagent, the primary reason for taking precautions to exclude water is to prevent the Grignard reagent from reacting with water. When Grignard reagents come into contact with water, they react to form a corresponding alkane and magnesium hydroxide, which results in the loss of the reactive Grignard species and reduces the yield of the desired product.
Therefore, it's essential to exclude water to achieve a higher yield of the Grignard reaction, making option b) the correct answer. Grignard reagents are highly reactive towards water and other protic solvents due to the presence of the magnesium-carbon bond, which is polar and has substantial ionic character.
The primary reason for taking precautions to exclude water in a reaction involving a Grignard reagent is to prevent the production of the benzene impurity. Grignard reagents are highly reactive with water and can react to form undesirable byproducts instead of the intended product. Therefore, it is important to keep the reaction environment dry to ensure the desired reaction proceeds as planned.
