Chemistry - Complete s-block Question with Solution | TestHub
Covalent character in ionic bond is compared with the help of Fajan's rule. According to Fajan's rule as polarising power of cation and polarisibility of anion increases covalent character in ionic bond increases on that basis we compare various properties of molecule. Solubility primarily depends on hydration and lattice energy and thermal stability primarily depends on covalent nature and lattice energy depending on type of anion in the salt. On the other hand, melting point increases with lattice energy and decreases with covalent nature.
Column I (Radicals) | Column II (Property having increasing order down the group) |
|---|---|
(P) Perchlorates of Alkali metals | (1) Melting point |
(Q) Chlorides of Alkali metals | (2) Lattice energy |
(R) Fluorides of Alkaline earth metals | (3) Thermal stability |
(S) Hydroxides of Alkaline earth metals | (4) Solubility in H2O |
| (5) Covalent character |
| (6) Ionic character |
Which of the following match is CORRECT?
Options:
Answer:
Solution:
(A) Alkali perchlorates get less soluble down the group, and covalent character falls: wrong.
(B) Alkali chloride lattice energy decreases down the group: wrong.
(C) Fluoride lattice energy decreases down the group: wrong.
(D) Hydroxide solubility and ionic character both increase down the group: correct.
Answer: (D).
