The process used for the removal of hardness of water is

Options

A. Calgon
B. Baeyer
C. Serpeck
D. Hoope

Answer

To solve the question regarding the process used for the removal of hardness of water, let's go through the steps systematically.

### Step 1: Understand Water Hardness
Water hardness is primarily caused by the presence of dissolved minerals, mainly calcium (Ca²⁺) and magnesium (Mg²⁺) ions. These ions can form insoluble precipitates with soap, making it difficult for soap to lather and leading to scale formation in pipes and appliances.

**Hint:** Identify the main ions responsible for water hardness.

### Step 2: Identify Common Methods for Removing Hardness
There are several methods to remove hardness from water, including:
- **Ion Exchange Process:** This method involves exchanging calcium and magnesium ions with sodium ions using a resin.
- **Lime Softening:** Adding lime (calcium hydroxide) to precipitate calcium and magnesium as insoluble carbonates.
- **Chelation:** Using chelating agents that can bind to calcium and magnesium ions, preventing them from causing hardness.

**Hint:** Recall the common methods used in water treatment for hardness removal.

### Step 3: Recognize the Correct Process
From the video transcript, the Kellgren process is mentioned as a method for removing hardness from water. This process involves the use of a chelating agent (like sodium phosphates) that reacts with calcium and magnesium ions, forming complexes that prevent these ions from contributing to hardness.

**Hint:** Focus on the specific processes mentioned in your study materials that are known for hardness removal.

### Step 4: Evaluate the Options
The question provides multiple-choice options (A, B, C, D). Based on the information gathered:
- **Option A:** Kellgren process (correct)
- **Option B:** Bayer process (not related to water hardness)
- **Option C:** Hall-Heroult process (not related to water hardness)
- **Option D:** Other processes (not related to water hardness)

**Hint:** Cross-check the options against the methods you have learned.

### Step 5: Conclusion
The correct answer to the question about the process used for the removal of hardness of water is **Option A: Kellgren process**.

### Summary
The process used for the removal of hardness of water is the Kellgren process, which involves the use of chelating agents to bind calcium and magnesium ions.

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