Assertion: Common name of 1,1-dichloroethane is ethylidene chloride.
Reason: Ethylidene chloride is a gem-dihalide.

Options

A. If both assertion and reason are true and reason Is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assetion is true but reason is false.
D. If both assertion and reason are false.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that the common name of 1,1-dichloroethane is ethylidene chloride.

1,1-Dichloroethane has the following structure:
```
Cl
|
CH3-CH
|
Cl
```
In this structure, both chlorine atoms (Cl) are attached to the same carbon atom, which is the first carbon in the ethane chain. The common name for this compound is indeed ethylidene chloride.

### Step 2: Understand the Reason
The reason states that ethylidene chloride is a gem-dihalide.

A gem-dihalide is defined as a compound where two halogen atoms are attached to the same carbon atom. Since in 1,1-dichloroethane (or ethylidene chloride), both chlorine atoms are on the same carbon, it qualifies as a gem-dihalide.

### Step 3: Conclusion
Both the assertion and the reason are true. Furthermore, the reason correctly explains the assertion since ethylidene chloride is indeed a gem-dihalide.

### Final Answer
Thus, the correct option is:
**Option A: Both assertion and reason are true, and reason is the correct explanation of assertion.**

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