Read the given statements and mark the correct option.
Statement 1 : The molecular mass of every two adjacent members of a homologous series differ by `14` u.
Statement 2 : All compounds in a homologous series are composed of same elements and contain the same functional group.

Options

A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C. Statement 1 is true but statement 2 is false.
D. Both statements 1 and 2 are false.

Explanation

To solve the question, we need to analyze the two statements provided and determine their validity.

### Step 1: Analyze Statement 1
**Statement 1:** The molecular mass of every two adjacent members of a homologous series differs by `14` u.

- A homologous series is a series of organic compounds that have the same functional group and similar chemical properties, but differ by a specific structural unit.
- In the case of alkanes, for example, each successive member differs by a `-CH2-` group, which has a molecular mass of `14` u (since carbon has an atomic mass of approximately `12` u and hydrogen has an atomic mass of approximately `1` u).
- Therefore, this statement is **true**.

### Step 2: Analyze Statement 2
**Statement 2:** All compounds in a homologous series are composed of the same elements and contain the same functional group.

- By definition, members of a homologous series do indeed contain the same functional group, which gives them similar chemical properties.
- Additionally, they are composed of the same elements, typically carbon and hydrogen, but can also include other elements depending on the functional group.
- Thus, this statement is also **true**.

### Step 3: Determine the Relationship Between the Statements
- While both statements are true, we need to assess whether Statement 2 provides a correct explanation for Statement 1.
- Statement 1 discusses the difference in molecular mass between adjacent members, while Statement 2 explains the composition and functional group of the compounds.
- Since Statement 2 does not explain why the molecular mass differs by `14` u, it is not a correct explanation of Statement 1.

### Conclusion
Both statements are true, but Statement 2 is not the correct explanation for Statement 1. Therefore, the correct option is:

**Option B:** Both statements are true, but Statement 2 is not the correct explanation of Statement 1.

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