Question

The reaction of ethanoyl chloride with sodium ethanoate gives (a) Ethyl ethanoate (b) ethanoic anhydride (c) Butane-2,3-dione (d) sodium 3 -oxobutanoate

Short answer

Answer: The product formed is ethanoic anhydride.

Step-by-step solution

Write chemical formulas.

Write the chemical formulas for ethanoyl chloride and sodium ethanoate: Ethanoyl chloride: CH3COCl Sodium ethanoate: CH3COONa

Predict the reaction and products formed.

Ethanoyl chloride is an acid chloride, and sodium ethanoate is a carboxylate salt. Acid chlorides react with carboxylate salts to form anhydrides. In this case, the reaction is between two ethanoyl groups, so ethanoic anhydride is formed. The acid chloride's chloride ion, when removed, bonds with the sodium ion from sodium ethanoate, forming sodium chloride as the second product. The chemical equation for the reaction is: CH3COCl + CH3COONa -> (CH3CO)2O + NaCl

Match the product with given options.

Now, we will match the chemical formula of the product with the given options: (a) Ethyl ethanoate: CH3COOCH2CH3 (b) Ethanoic anhydride: (CH3CO)2O (c) Butane-2,3-dione: CH3COCOCH3 (d) Sodium 3-oxobutanoate: CH3CH2COONa The correct product formed is ethanoic anhydride, which matches with option (b). Therefore, the reaction of ethanoyl chloride with sodium ethanoate yields ethanoic anhydride.

Key concepts

Acid Chloride Reactions

Acid chlorides are highly reactive compounds in organic chemistry, known for their role in various synthesis reactions. They feature a carbon atom double-bonded to an oxygen atom and bonded to a chlorine atom, designated as -COCl. When react with a variety of nucleophiles, they can form different products including esters, amides, and anhydrides.

For example, during the reaction with carboxylate salts, the acid chloride reacts in a way where the chlorine atom is substituted by the carboxylate group. This type of reaction is a nucleophilic acyl substitution, where the nucleophilic carboxylate attacks the electrophilic carbon of the acid chloride. When ethanoyl chloride reacts with sodium ethanoate, it forms ethanoic anhydride and sodium chloride as byproduct.

Understanding these reactions requires comprehending the reactivity of carbonyl compounds and the influence of leaving groups, such as chloride. Acid chlorides are particularly interesting because of their high reactivity, which makes them useful intermediates in organic synthesis.

Carboxylate Salts

Carboxylate salts are the ionic compounds that result from the deprotonation of carboxylic acids. They consist of a carboxylate anion (R-COO-) and a cation, typically a metal such as sodium or potassium. Due to their ionic nature, carboxylate salts are often soluble in water and can readily dissociate into their constituent ions.

When they react with acid chlorides, the nucleophilic carboxylate anion can attack the electrophilic carbonyl carbon, displacing the chloride ion. This leads to the formation of carboxylic anhydrides, illustrating the nucleophilic acyl substitution mechanism. These reactions are not only important in laboratory synthesis but also play a crucial role in industrial processes for the manufacture of various organic compounds.

Carboxylate salts are typically obtained by neutralizing carboxylic acids with a base. Their reactivity makes them useful building blocks in organic synthesis, especially in the formation of more complex organic molecules through processes like esterification and anhydride formation.

Organic Synthesis

Organic synthesis is the process by which organic compounds are constructed from simpler substances. It involves the deliberate manipulation of chemical reactions to obtain a desired product. In the context of acid chloride and carboxylate reactions, these processes can be harnessed to create a wide variety of chemical substances including pharmaceuticals, polymers, and agrochemicals.

One of the cornerstones of organic synthesis is the ability to form bonds between carbon atoms or between carbon and other elements such as oxygen or nitrogen. Anhydrides, such as ethanoic anhydride, are formed via a nucleophilic substitution reaction that is a key transformation in synthesis. The principle behind creating such molecules lies in understanding the reactivity patterns and how different functional groups interact with each other.

In designing synthetic routes, chemists look for ways to increase efficiency, yield, and selectivity of the reactions, often using catalysts or specific reaction conditions to steer the chemical transformations. Organic synthesis not only expands the library of known organic compounds but also provides foundational techniques and reactions that are essential for advancing research and industrial applications.