Problem 64 - A Complete Resource Book in Chemistry for JEE Main

Question

Hydrolysis of \(\mathrm{NCl}_{3}\) gives \(\mathrm{NH}_{3}\) and \(\mathrm{X}\). Which of the following is \(\mathrm{X} ?\) (a) \(\mathrm{HClO}_{4}\) (b) \(\mathrm{HClO}_{3}\) (c) \(\mathrm{HOCl}\) (d) \(\mathrm{HClO}_{2}\)

Step-by-Step Solution

Answer

The compound \( \mathrm{X} \) is \( \mathrm{HOCl} \) (option c).

Step 1: Understanding Hydrolysis

Hydrolysis is a chemical reaction where water is used to break down a compound. In this question, we're told that \( \mathrm{NCl}_3 \) undergoes hydrolysis to form \( \mathrm{NH}_3 \) and another compound \( \mathrm{X} \). We need to determine what \( \mathrm{X} \) is.

Step 2: Writing the Balanced Equation

During hydrolysis, each molecule of \( \mathrm{NCl}_3 \) reacts with water \( \mathrm{H}_2\mathrm{O} \). For the hydrolysis of \( \mathrm{NCl}_3 \), the balanced chemical equation is:\[ \mathrm{NCl}_3 + 3\mathrm{H}_2\mathrm{O} \rightarrow \mathrm{NH}_3 + 3\mathrm{HOCl}. \]

Step 3: Analyzing the Products

From the balanced equation, the products of the hydrolysis reaction of \( \mathrm{NCl}_3 \) are \( \mathrm{NH}_3 \) and \( \mathrm{HOCl} \). Therefore, the compound \( \mathrm{X} \) in the reaction is \( \mathrm{HOCl} \), which is also known as hypochlorous acid.

Step 4: Matching with the Options Provided

Now, we match \( \mathrm{HOCl} \) with the options provided:- (a) \( \mathrm{HClO}_4 \)- (b) \( \mathrm{HClO}_3 \)- (c) \( \mathrm{HOCl} \)- (d) \( \mathrm{HClO}_2 \)The correct match for \( \mathrm{HOCl} \) is option (c).

Key Concepts

Hydrolysis

Hydrolysis is an essential chemical process where water is used to split a compound. It's like nature's way of breaking things down. Imagine you have a stick of rock candy, and you're using water to slowly dissolve it. In chemistry, hydrolysis involves the breakage of bonds in molecules using water.
For instance, in the exercise, nitrogen trichloride ( NCl_3 ) undergoes hydrolysis. In this reaction, it reacts with water ( H_2O ) to form ammonia ( NH_3 ) and hypochlorous acid ( HOCl ). Understanding this process is essential to predict the chemical products of reactions involving water.
Key points to remember about hydrolysis:

• Water is the key player in breaking bonds.
• Hydrolysis products often include acids or bases.
• The specific products can vary depending on the original compound undergoing hydrolysis.

Knowing how hydrolysis operates helps in predicting the outcomes of many chemical reactions.

Balanced Chemical Equation

A balanced chemical equation is pivotal in chemistry. It ensures that the number of atoms for each element is the same on both sides of the equation. This balance is vital because of the law of conservation of mass, which states that matter cannot be created or destroyed.
When balancing equations, it is important to adjust coefficients—not subscripts—to ensure the atoms balance. In the hydrolysis of NCl_3, the balanced equation is:\[ \mathrm{NCl}_3 + 3\mathrm{H}_2\mathrm{O} \rightarrow \mathrm{NH}_3 + 3\mathrm{HOCl}. \]In this equation:

• 1 molecule of NCl_3 reacts with 3 molecules of H_2O.
• The reaction produces 1 molecule of NH_3 and 3 molecules of HOCl.

Every chemical equation you encounter in your studies should be balanced just like this for accurate representation of the reaction. It helps us understand how reactants transform into products on a molecular level.

Hypochlorous Acid

Hypochlorous acid ( HOCl ) is a weak acid that plays a crucial role in various chemical and biological processes. This compound is one of the products of the hydrolysis reaction involving NCl_3 .
HOCl is known for several applications, especially in sanitization and disinfection due to its powerful oxidizing properties. When produced in cells, it serves as a defense mechanism against pathogens by white blood cells.
Here are some interesting facts about hypochlorous acid:

• Commonly used in cleaning products for its germicidal properties.
• Non-toxic and safe for use on surfaces and even certain food products.
• In biological systems, it helps to neutralize bacteria and viruses effectively.

Understanding the chemical nature and applications of hypochlorous acid enhances our ability to utilize it effectively, both in industrial applications and in healthcare.