Problem 3 - Chemistry in 30 days

Question

When chlorine is passed through concentrated hot solution of \(\mathrm{KOH}\), the compound formed is (a) \(\mathrm{KClO}\) (b) \(\mathrm{KClO}_{2}\) (c) \(\mathrm{KClO}_{3}\) (d) \(\mathrm{KClO}_{4}\)

Step-by-Step Solution

Answer

The compound formed is KClO₃, corresponding to option (c).

Step 1: Identify the Reaction Conditions

We are given that chlorine is passed through a concentrated hot solution of KOH. This suggests that the reaction conditions are both concentrated and hot, which will influence the type of reaction that occurs.

Step 2: Recall Relevant Chemical Reaction

Recall the chemical reaction for chlorine gas reacting with hot, concentrated \ \ \( \text{KOH} \ \): \[\mathrm{3Cl_2 + 6KOH \rightarrow 5KCl + KClO_3 + 3H_2O} \]This reaction states that \ \(\text{KClO}_3\) (potassium chlorate) is formed as one of the products.

Step 3: Analyze the Products

The main products of the reaction include potassium chloride (KCl) and potassium chlorate (KClO₃). We are primarily interested in the oxychloride product, which in this case is KClO₃.

Step 4: Choose the Correct Option

From the given options: (a) KClO (b) KClO₂ (c) KClO₃ (d) KClO₄, the correct answer is (c) KClO₃, as this is the product formed when chlorine reacts with hot, concentrated KOH.

Key Concepts

Chlorine and KOH Reaction

When chlorine gas is bubbled into a concentrated hot solution of potassium hydroxide, a unique chemical reaction unfolds. This specific interaction is influenced by the conditions both in the concentration and temperature of KOH. Under heated, concentrated conditions, chlorine reacts in a manner that typically leads to a rearrangement of the elements involved.
In simple terms, during this reaction:

• Chlorine, initially a two-atom molecule, dissociates and engages with potassium and hydroxide ions present.
• This leads to the formation of potassium chloride (KCl) and potassium chlorate (KClO₃) along with water (H₂O).

The chemical equation representing this reaction is:\[\mathrm{3Cl_2 + 6KOH \rightarrow 5KCl + KClO_3 + 3H_2O} \]Understanding this process is crucial as it sheds light on how elemental chlorine can transform into oxychlorides under specific conditions.

Oxychlorides of Chlorine

The term "oxychlorides" refers to compounds where chlorine is bonded to oxygen. In this reaction with potassium hydroxide, one of the products is potassium chlorate ( KClO₃), which is a type of oxychloride.
To comprehend why KClO₃ forms during the reaction:

• We need to look at chlorine's ability to bond not only with metals but also with oxygen.
• This dual binding capacity allows it to form a structure containing both chlorine and oxygen, known as an oxychloride.

Potassium chlorate, the key oxychloride formed, is often used in applications requiring an oxygen-rich substance, such as explosives and firework compositions.
This highlights how versatile chlorine can be when interacting with other elements, especially under varied chemical environments.

Chemical Reactions in Inorganic Chemistry

Inorganic chemistry explores reactions involving non-organic compounds. The reaction between chlorine and potassium hydroxide is a quintessential example of an inorganic chemical reaction. Such reactions emphasize the importance of conditions like temperature and concentration in determining the products formed.
To understand these reactions:

• It's vital to grasp how elemental substances like chlorine react under different conditions.
• Inorganic reactions often involve shifts in oxidation states, as seen when chlorine turns into oxychlorides like KClO₃.

This focus on reactant conditions and their resultant products forms the core of studying inorganic chemical reactions. This knowledge is crucial for predicting and controlling reactions in laboratory and industrial processes, highlighting the practical applications and significance of inorganic chemistry in real-world scenarios.