Question

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. Choose the correct option:

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Glucose reactions: Bromine water → oxidizes aldehyde to gluconic acid Shows presence of carbonyl group in open-chain form.

Answer 1

The Correct Option is C

To solve this question, let us analyze both the assertion and the reason separately:

1. Assertion (A): Glucose gets oxidized to six carbon gluconic acid on reaction with bromine water.
   • The statement is true. Glucose, when reacted with bromine water, is oxidized at the aldehyde group to form gluconic acid. Bromine water is a mild oxidizing agent that specifically oxidizes the aldehyde group in glucose to a carboxylic acid, resulting in gluconic acid, which has six carbon atoms like glucose.
2. Reason (R): The carbonyl group is absent in the open chain structure of glucose.
   • This statement is false. In the open-chain form of glucose, a carbonyl group is indeed present; it is the aldehyde group (-CHO) at the first carbon atom. This aldehyde group is crucial for the oxidation reaction where glucose is converted to gluconic acid.

Now, evaluating the options:

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • This option is incorrect because although the assertion is true, the reason is false.
• Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • This option is incorrect because while the assertion is true, the reason is false.
• Assertion (A) is true, but Reason (R) is false.
  • This option is correct as it correctly identifies the truth of the assertion and the falsity of the reason.
• Assertion (A) is false, but Reason (R) is true.
  • This option is incorrect because the assertion is true and the reason is false.

Thus, the correct answer is that Assertion (A) is true, but Reason (R) is false.