Step 1:The element of the 3d series with the lowest enthalpy of atomisation is copper (Cu). Copper has a completely filled \( 3d^{10} \) configuration, which makes it highly stable. The stability of the \( 3d^{10} \) configuration reduces the energy required to break the metallic bonds during atomisation, hence lowering the enthalpy of atomisation. In contrast, elements like zinc (Zn) and manganese (Mn) have less stable electron configurations and require more energy to break the bonds during atomisation.
Step 2: Thus, copper (Cu) has the lowest enthalpy of atomisation due to the stability provided by its filled \( 3d^{10} \) configuration. \bigskip
(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.