Chemistry - PERIODIC TABLE Question with Solution | TestHub
NaF is predominately ionic and if the cationic part of the compound is replaced by potassium ion. Then which of the value of given properties decreases in the formed compound.
(i) Melting point (ii) Lattice energy
(iii) Solubility in water (iv) Thermal stability
(v) Covalent character.
Answer:
Solution:
When NaF (ionic) has Na⁺ replaced by K⁺, forming KF, the ionic radius increases (Na⁺ < K⁺). This leads to a decrease in lattice energy, melting point, and thermal stability. Solubility in water generally increases with decreasing lattice energy. Covalent character decreases due to increased ionic character.
Therefore, (i) Melting point, (ii) Lattice energy, and (iv) Thermal stability decrease. (v) Covalent character also decreases. (iii) Solubility in water generally increases.
The properties that decrease are (i), (ii), (iv), and (v).