Ethanal to But-2-enal
1.The conversion of Ethanal (Acetaldehyde) to But-2-enal involves an aldol condensation reaction. The steps are: 1. Aldol condensation: Ethanal undergoes aldol condensation in the presence of a base like NaOH to form But-3-en-2-al (crotonaldehyde). \[ \text{CH}_3\text{CHO} + \text{CH}_3\text{CHO} \xrightarrow{\text{NaOH}} \text{CH}_3\text{CH=CHCHO} \quad (\text{But-3-en-2-al}) \] 2. The final product is But-2-enal, which is the desired compound. \vspace{10pt}
(a) State the following:
(i) Kohlrausch law of independent migration of ions
A solution of glucose (molar mass = 180 g mol\(^{-1}\)) in water has a boiling point of 100.20°C. Calculate the freezing point of the same solution. Molal constants for water \(K_f\) and \(K_b\) are 1.86 K kg mol\(^{-1}\) and 0.512 K kg mol\(^{-1}\) respectively.
Write the reactions involved when D-glucose is treated with the following reagents: (a) HCN (b) Br\(_2\) water
Identify A and B in each of the following reaction sequence:
(a) \[ CH_3CH_2Cl \xrightarrow{NaCN} A \xrightarrow{H_2/Ni} B \]
(b) \[ C_6H_5NH_2 \xrightarrow{NaNO_2/HCl} A \xrightarrow{C_6H_5NH_2} B \]
Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition reactions than propanal? Justify your answer.