Assertion (A) : Glucose gets oxidized to six carbon gluconic acid on reaction with bromine water.
Reason (R) : The carbonyl group is absent in the open chain structure of glucose.
Reason (R) : The carbonyl group is absent in the open chain structure of glucose.
Show Hint
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
The Correct Option is C
Solution and Explanation
Bromine water (\( \text{Br}_2/\text{H}_2\text{O} \)) is a mild oxidizing agent. It is strong enough to oxidize the aldehyde group (\(-\text{CHO}\)) of glucose to a carboxylic acid group (\(-\text{COOH}\)), but not strong enough to oxidize the alcohol groups. The resulting 6-carbon mono-carboxylic acid is called gluconic acid. Thus, the Assertion is True.
Step 2: Evaluating the Reason.
The open-chain structure of glucose does contain a carbonyl group (specifically an aldehyde group at C-1). This is proven by various reactions such as the formation of an oxime with hydroxylamine and a cyanohydrin with hydrogen cyanide. Therefore, the statement that the carbonyl group is "absent" is scientifically False.
Step 3: Selecting the correct code.
Since the Assertion is a factually correct statement and the Reason is factually incorrect, the correct option is (C). Final Answer: (C) Assertion (A) is true, but Reason (R) is false.
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