NCERT Solutions for Chapter: Aldehydes, Ketones and Carboxylic Acids, Exercise 6: Long Answer Type

An alkene $‘\mathrm{A}’$ (Mol. formula ${\mathrm{C}}_5{\mathrm{H}}_{10}$) on ozonolysis gives a mixture of two compounds $‘\mathrm{B}’$ and $‘\mathrm{C}’$. Compound $‘\mathrm{B}’$ gives positive Fehling’s test and also forms iodoform on treatment with ${\mathrm{I}}_2$ and $\mathrm{NaOH}$. Compound $‘\mathrm{C}’$ does not give Fehling’s test but forms iodoform. Identify the compounds $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$. Write the reaction for ozonolysis and formation of iodoform from $\mathrm{B}$ and $\mathrm{C}$.

An aromatic compound $‘\mathrm{A}’$ (Molecular formula ${\mathrm{C}}_8{\mathrm{H}}_8\mathrm{O}$) gives positive $2, 4-\mathrm{DNP}$ test. It gives a yellow precipitate of compound $‘\mathrm{B}’$ on treatment with iodine and sodium hydroxide solution. Compound $‘\mathrm{A}’$ does not give Tollen’s or Fehling’s test. On drastic oxidation with potassium permanganate it forms a carboxylic acid $‘\mathrm{C}’$ (Molecular formula ${\mathrm{C}}_7{\mathrm{H}}_6{\mathrm{O}}_2$), which is also formed along with the yellow compound in the above reaction. Identify $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ and write all the reactions involved.

Write down functional isomers of a carbonyl compound with molecular formula ${\mathrm{C}}_3{\mathrm{H}}_6\mathrm{O}$. Which isomer will react faster with $\mathrm{HCN}$ and why? Explain the mechanism of the reaction also. Will the reaction lead to the completion with the conversion of whole reactant into product at reaction conditions? If a strong acid is added to the reaction mixture what will be the effect on concentration of the product and why?

When liquid $‘\mathrm{A}’$ is treated with a freshly prepared ammoniacal silver nitrate solution, it gives bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogen sulphite. Liquid $‘\mathrm{B}’$ also forms a white crystalline solid with sodium hydrogen sulphite but it does not give test with ammoniacal silver nitrate. Which of the two liquids is aldehyde? Write the chemical equations of these reactions also.