Chemistry - CHEMICAL BONDING 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 (Molecular species) | Column II (Properties) |
|---|---|
(P) Li2CO3 < Na2CO3 < K2CO3 < Rb2CO3 | (1) Thermal stability |
(Q) BeO < MgO < CaO < SrO < BaO | (2) % Ionic character |
(R) BeSO4 > MgSO4 > CaSO4 > SrSO4 > BaSO4 | (3) Lattice energy |
(S) BeC2O4 > MgC2O4 > CaC2O4 > SrC2O4 | (4) Solubility in water |
| (5) Basic nature of oxide |
| (6) Melting point |
Which of the following option has the INCORRECT combination considering Column I and Column II?
Options:
Answer:
Solution:
(A) Sulphates: BeSO4 is most soluble, solubility falls down the group: valid.
(B) Oxide basic nature rises BeO to BaO: valid.
(C) Oxalate lattice energy falls down the group: valid.
(D) Oxalate thermal stability rises down the group, but the order shown falls: invalid.
Answer: (D).
