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.
Answer the following by appropriately matching the lists based on the information given in the paragraph
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 CORRECT combination considering Column I and Column II?
Options:
Answer:
Solution:
Each order in Column I runs down the group, left to right.
Down the group, alkali carbonates become more thermally stable, so P→1 holds.
Lattice energy decreases down the group, so P→3 and Q→3 fail.
Q shows rising basic nature of oxides, not thermal stability.
Answer: (A).
