31.

Give a reason for the following:

Gelatin is added to ice creams.

For the complex ion [Fe(CN)₆]^3-, state:

(i) The type of hybridisation

(ii) The magnetic behaviour

(iii) The oxidation number of the central metal atom

Write the IUPAC name of [Co(en)₂Cl₂]⁺ ion and draw the structure of its geometrical isomers.

Explain why :

Mn²⁺ is more stable than Fe²⁺ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)

Explain why:

Transition elements usually form coloured ions.

Explain why:

Zr and Hf exhibit similar properties.

Complete and balance the following chemical equations:$$\begin{gathered} \left(\mathrm{i}\right) {\mathrm{KMnO}}_4 + \mathrm{KI} + {\mathrm{H}}_2{\mathrm{SO}}_4 \stackrel{ }{\to } \mathrm{\_\_}+\mathrm{\_\_\_}+\mathrm{\_\_\_\_}+\mathrm{\_\_} \\ \left(\mathrm{ii}\right) {\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7 + {\mathrm{H}}_2{\mathrm{SO}}_4 + {\mathrm{H}}_2\mathrm{S}\stackrel{ }{\to } \mathrm{\_\_} + \mathrm{\_\_\_}+ \mathrm{\_\_\_}+ \mathrm{\_\_} \\ \left(\mathrm{iii}\right) {\mathrm{KMnO}}_4 + {\mathrm{H}}_2{\mathrm{SO}}_4 + {\mathrm{FeSO}}_4\stackrel{ }{\to } \mathrm{\_\_} + \mathrm{\_\_\_}+ \mathrm{\_\_\_\_} +\mathrm{\_\_} \end{gathered}$$

Arrange the following in the increasing order of their basic strength:

C₂H₅NH₂, C₆H₅NH₂, (C₂H₅)₂NH

Give a balanced chemical equation of convert methyl cyanide to ethyl alcohol.

What happens when benzene diazonium chloride reacts with phenol in weak alkaline medium? (Give balanced equation).