Bleaching powder loses its power on keeping for a long time
because

Options

A. It absorbs moisture
B. It changes into calcium hypochlorite
C. It changes into calcium chloride and calcium chlorate
D. It cahnges salt of calcium chloride and calcium hydroxide

Answer

To understand why bleaching powder loses its effectiveness over time, we can break down the explanation into clear steps:

### Step 1: Identify the Composition of Bleaching Powder
Bleaching powder is primarily composed of calcium hypochlorite, which has the chemical formula Ca(OCl)₂.

### Step 2: Understand the Stability of Bleaching Powder
Bleaching powder is a strong oxidizing agent, and its stability can be affected by environmental factors such as moisture and temperature.

### Step 3: Explain the Decomposition Process
When bleaching powder is stored for a long time, it undergoes a process known as auto-oxidation. During this process, calcium hypochlorite decomposes into other compounds.

### Step 4: Identify the Products of Decomposition
The auto-oxidation of calcium hypochlorite leads to the formation of calcium chlorate (Ca(ClO)₂) and calcium chloride (CaCl₂). The reaction can be represented as:
\[ 2 \text{Ca(OCl)}_2 \rightarrow \text{Ca(ClO)}_2 + \text{CaCl}_2 \]

### Step 5: Conclusion
As a result of this decomposition, the bleaching power of the powder diminishes because the active chlorine content decreases, making it less effective as a bleaching agent.

### Final Answer
Bleaching powder loses its power on keeping for a long time because it undergoes auto-oxidation, leading to the formation of calcium chlorate and calcium chloride.

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