Assertion (A): Third member of alkane is propane `(C_(3)H_(8))`
Reason (R): It is obtained from general formula `C_(n)H_(2n+2)`

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Explanation

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

**Step 1: Understand the Assertion (A)**
The assertion states that the third member of the alkane series is propane, which has the molecular formula \( C_3H_8 \).

**Step 2: Verify the Assertion**
Alkanes follow a specific pattern based on their number of carbon atoms. The general formula for alkanes is \( C_nH_{2n+2} \).
- For \( n = 1 \): \( C_1H_{2(1)+2} = C_1H_4 \) (Methane, \( CH_4 \))
- For \( n = 2 \): \( C_2H_{2(2)+2} = C_2H_6 \) (Ethane, \( C_2H_6 \))
- For \( n = 3 \): \( C_3H_{2(3)+2} = C_3H_8 \) (Propane, \( C_3H_8 \))

Thus, the assertion is correct.

**Step 3: Understand the Reason (R)**
The reason states that propane is obtained from the general formula \( C_nH_{2n+2} \).

**Step 4: Verify the Reason**
The general formula for alkanes is indeed \( C_nH_{2n+2} \). This formula applies to all alkanes, including propane. Therefore, the reason is also correct.

**Step 5: Conclusion**
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the correct answer is that both statements are true, and the reason supports the assertion.

### Final Answer:
Both Assertion (A) and Reason (R) are true, and the reason is correct for the assertion.

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