Problem 218 - A Complete Resource Book in Chemistry for JEE Main

Question

On mixing ethyl acetate with aqueous sodium chloride, the composition of the resultant solution is (a) \(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5}+\mathrm{NaCl}\) (b) \(\mathrm{CH}_{3} \mathrm{COONa}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{COCl}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}+\mathrm{NaOH}\) (d) \(\mathrm{CH}_{3} \mathrm{Cl}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COONa}\)

Step-by-Step Solution

Answer

The composition is (a) \(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5} + \mathrm{NaCl}\).

Step 1: Identify Components Involved

We begin by identifying the components involved in the mixing process. The compounds are ethyl acetate (\(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5}\)) and aqueous sodium chloride (\(\mathrm{NaCl}\)). Ethyl acetate is a commonly used ester, and sodium chloride is a soluble ionic compound in water.

Step 2: Understand the Reaction Type

Consider the potential reaction between an ester and an ionic salt in aqueous solution. Typically, esters do not react significantly with salts like sodium chloride (\(\mathrm{NaCl}\)) under normal conditions because there is no strong driving force for a reaction. No chemical reaction occurs that would lead to the breakdown of ethyl acetate with sodium chloride.

Step 3: Evaluate provided options

We need to evaluate each provided option based on the expected mixture of ethyl acetate and sodium chloride. (a) \(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5} + \mathrm{NaCl}\) represents the initial state with no reaction.(b) \(\mathrm{CH}_{3} \mathrm{COONa} + \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) suggests the ester undergoes saponification or hydrolysis, which requires a base, not \(\mathrm{NaCl}\).(c) \(\mathrm{CH}_{3} \mathrm{COCl} + \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH} + \mathrm{NaOH}\) includes components absent from the reactant list, so it cannot be formed.(d) \(\mathrm{CH}_{3} \mathrm{Cl} + \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COONa}\) also does not follow from any logical ester-salt interaction.

Step 4: Conclusion

Since there is no catalyst or additional reactants to instigate a reaction between ethyl acetate \(\mathrm{CH}_3 \mathrm{COOC}_2 \mathrm{H}_5\) and sodium chloride \(\mathrm{NaCl}\), the composition of the solution remains unchanged as the initial mixture described in option (a): \(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5} + \mathrm{NaCl}\).

Key Concepts

Ester and Ionic Salt Interaction

When exploring the interaction between esters and ionic salts, it's essential to understand the nature of these compounds. Esters, such as ethyl acetate, are organic compounds formed from an alcohol and a carboxylic acid. They are characterized by their pleasant aromas and are commonly used as solvents.
In contrast, ionic salts like sodium chloride are composed of charged ions, which are held together by ionic bonds. They readily dissolve in water to give ions, such as sodium ions \(\mathrm{Na}^{+}\) and chloride ions \(\mathrm{Cl}^{-}\).

• Esters typically do not participate in chemical reactions with ionic salts like sodium chloride when in aqueous solutions.
• The lack of interaction is due to the absence of reactive conditions or catalysts that would facilitate a bond-breaking or bond-forming event.

Without an external catalyst or harsh conditions such as the presence of a strong acid or base, the mixture remains as separate ethyl acetate and sodium chloride in water.

Ethyl Acetate Properties

Ethyl acetate \(\mathrm{CH}_{3}\mathrm{COOC}_{2}\mathrm{H}_{5}\) is a clear, colorless liquid with a sweet, fruity odor. Its properties make it a versatile chemical used in various industries—from perfumes and flavorings to coatings and adhesives.
Key Properties of Ethyl Acetate:

• Boiling Point: It has a boiling point of about 77 °C, allowing it to evaporate quickly.
• Solubility: While slightly soluble in water, it is completely miscible with many organic solvents, enhancing its usefulness as a solvent.
• Chemical Stability: Ethyl acetate is relatively stable but may undergo hydrolysis in the presence of strong acids or bases to form ethanol and acetic acid.

Understanding these properties is crucial for predicting its behavior in various chemical environments, such as interactions with esters or potential reactions with salts.

Reaction Types with Salts

The interaction of organic compounds such as esters with salts can vary greatly depending on the chemical environment. Generally, the reaction type is determined by the solubility and reactivity of the compounds at hand.
Some reactions involving salts include:

• Precipitation Reactions: These occur when two aqueous solutions form a solid, known as a precipitate, due to the low solubility of the resulting compound. However, this does not apply to ethyl acetate and sodium chloride, as no such insoluble compound forms from their mixture.
• Acid-Base Reactions: In the presence of an acid or base, esters might react to produce salts. For instance, ethyl acetate can undergo saponification in the presence of a strong base (like NaOH), forming an alcohol and a salt (such as sodium acetate).
• Redox Reactions: These involve the transfer of electrons between species; esters and simple ionic salts like NaCl generally do not partake in such reactions due to a lack of electron-transfer potential.

With typical esters and salts, without acidic or basic conditions, reactions are unlikely, allowing each compound to retain its initial state when simply mixed in an aqueous solution.