Consider the following set of ions: Al3+; Li+, Rb+, [(C4H9)4N+].

a). Which of these ions will form the largest hydrated ion(s)?

b). which cation(s) will be hydrophobic structure makers?

c).Which ion attaches the fewest water molecules when it dissolves in water?

d).Which ion is most likely to be an electrostatic structure breaker?

e).Which ion is most likely to be an electrostatic structure maker?

a) Cations which are lowest size generally forms adopts more number of water molecules around it. Such kind of Cations forms largest hydrated ions. Among given cations, Li+ is smallest one and (C4H9)4N+ is largest one. So, Li+ ion forms largest hydrated ion.

b) Organic ligands or alkyl chains contained Cations are hydrophobic in nature due to its low polar nature. Among given (C₄H₉)4N⁺ cation is hydrophobic in nature.

c) Size of cation inversely proportional to the hydrated sphere or number of water molecules attached. So, in the given Cations (C₄H₉)4N⁺ is largest cation which attaches fewest water molecules.

d) Charge on the cation makes it more electrostatic maker. But size is inversily proportional to electrostatic property. (C₄H₉)4N⁺ is electrostatic structure breaker.

e) Al⁺³ has highest charge. So it is most electrostatic structure maker.

Hope this helps!