Short Answer TypeGlucose on reaction with HI gives n-hexane. What does it suggest about the structure of glucose?
After the ban on plastic bags, students of a school decided to make people aware of the harmful effects of plastic bags on the environment and Yamuna River. To make the awareness more impactful, they organised a rally by partnering with other schools and distributed paper bags to vegetable vendors, shopkeepers and departmental stores. All the students pledged not to use polythene bags in the future to save the Yamuna River.
After reading the above passage, answer the following questions:
<(i) What values are shown by the students?
(ii) What are bio-degradable polymers? Give one example.
(iii) Is polythene a condensation or an addition polymer ?
(a) Write the mechanism of the following reaction :
CH3-CH2-OH 
CH3-CH2-Br + H2O
(b) Write the equation involved in Reimer-Tiemann reaction.
Give simple chemical tests to distinguish between the following pairs of compounds:
(i) Benzaldehyde and Benzoic acid
(ii) Propanal and Propanone
Account for the following:
(i) CH3CHO is more reactive than CH3 COCH3 towards reaction with HCN.
(ii) The carboxylic acid is a stronger acid than phenol.
(i) CH3COCH3 is sterically hindered than CH3CHO due to the presence of alkyl group on both sides of the carbonyl carbon, making them less reactive towards nucleophilic attack because both methyl groups have electron releasing tendency due to -I effect. These alkyl groups make ketone less reactive by donating an electron to a carbonyl group. Therefore, acetaldehyde is more reactive towards reaction with HCN.
(ii) Carboxylic acids are acidic due to resonance stabilisation of carboxylate anion and in phenols, the acidic character is present due to resonance stabilisation of phenoxide anion. Carboxylic acids are more acidic than phenols because the negative charge in carboxylate anion is more spread out compared to the phenoxide ion, as there are two electronegative O-atoms in carboxylate anion compared to one in phenoxide ion. In the resonance structures of carboxylate anion, the negative charge is present on the O-atoms, while in the resonance of phenoxide ion, a negative charge is also present on the electropositive carbon atom, which leads to less stability of phenoxide ion than carboxylate anion.
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