Question

A , B and C are divalent metals and their fluorides salts are AF2, BF2 and CF2

respectively. If size of their atoms are in the order A<B<C, arrange their fluorides

salts in increasing order of their covalent character? Which of these salts have

highest melting point?​

Answer 1

Answer:

Correct option is

A

NaF>KF>LiF>RbF>CsF , Melting point order

B

CuCl>NaCl , Covalent charater

C

BeSO

4

<CaSO

4

<SrSO

4

<BaSO

4

, Thermal stability order

A) The correct order for the decreasing melting points of alkali metal fluorides is NaF>KF>LiF>RbF>CsF.

With an increase in the atomic number of the alkali metal, the ionic character of the alkali metal fluoride increases and the melting point decreases.

Thus, option A is correct.

B) Copper (I) chloride is more covalent than NaCl. Sodium is highly electropositive metal (much more than copper). This results in higher ionic character for NaCl.

Thus, option B is correct.

C) As the atomic number of the alkaline earth metals increases, the thermal stability of the sulphates increases due to an increase in the lattice enthalpy.

Hence, the increasing order for the thermal stability of alkaline earth metal sulphates is BeSO

4

<CaSO

4

<SrSO

4

<BaSO

4

.

Thus, option C is correct.

D) With an increase in the atomic number of the alkali metals, the solubility of alkali metal iodides increases due to a decrease in the lattice energy.

The increasing order of the solubility of the alkali metal iodides is LiI<NaI<KI<RbI<CsI.

Hence, the option D is incorrect.

Solve any question of Chemical Bonding and Molecular Structure with:-