Why was the tert butyl chloride finally washed with water?
To get rid of the small amount of NaHCO3 left behind from the neutralization of acid used in the preparation of t-butyl chloride.
Tert-butyl chloride is typically washed with water after it has been synthesized to remove impurities. Water is a polar solvent, while tert-butyl chloride is nonpolar. This difference in polarity allows water to dissolve any polar impurities present in the tert-butyl chloride. By washing the tert-butyl chloride with water, the impurities are selectively removed, resulting in a purer final product.
Tert-butyl chloride is often washed with water as a final step in its preparation to remove impurities and byproducts. Water is added to the reaction mixture to dissolve water-soluble impurities and aid in their separation from the organic layer.
To understand why tert-butyl chloride is washed with water, let's break it down step by step:
1. The preparation of tert-butyl chloride typically involves the reaction between tert-butyl alcohol and hydrochloric acid. The reaction can be represented by the following equation:
tert-butyl alcohol + hydrochloric acid -> tert-butyl chloride + water
2. After the reaction is complete, tert-butyl chloride is formed along with water as a byproduct.
3. However, there might be impurities present in the reaction mixture, such as unreacted tert-butyl alcohol, hydrochloric acid, and other organic or inorganic compounds.
4. The addition of water to the reaction mixture helps to dissolve any water-soluble impurities. This includes water itself, unreacted tert-butyl alcohol, as well as hydrochloric acid.
5. Once the impurities are dissolved in the aqueous layer, they can be easily separated from the organic layer containing tert-butyl chloride. The organic layer is usually denser and immiscible with water, allowing for a simple separation by draining or decanting the aqueous layer.
6. By washing tert-butyl chloride with water, it ensures that most of the impurities are removed, resulting in a purer product.
Therefore, the final washing of tert-butyl chloride with water is done to enhance the purity of the compound by removing water-soluble impurities.