Among CaH 2, BeH 2, BaH 2, the order of ionic character is

Question

Among CaH 2, BeH 2, BaH 2, the order of ionic character is (A) BeH 2< BaH 2< CaH 2 (B) CaH 2< BeH 2< BaH 2 (C) BeH 2< CaH 2< BaH 2 (D) BaH 2< BeH 2< CaH 2

Tardigrade Admin · Accepted Answer

According to Fajan's rule, compounds with small cation, large anion, more charge on cation or anion shows more covalent character. As the above conditions opposes, it shows ionic character. Since, the size of cation decreases in the following order:

B a^{2 +} > C a^{2 +} > B e^{2 +}

Therefore, the correct order of ionic character will be

B e H_{2} < C a H_{2} < B a H_{2}

B e H_{2}

has some covalent character. It is because of the effect of polarisation. According to Fajan's rule, smaller the size of cation and more the charge on the cation, greater is its polarising power.
Thus,

B e H_{2}

has some covalent character also.

Q. Among $C a H_{2}, B e H_{2}, B a H_{2}$ , the order of ionic character is

$B e H_{2} < B a H_{2} < C a H_{2}$

$C a H_{2} < B e H_{2} < B a H_{2}$

$B e H_{2} < C a H_{2} < B a H_{2}$

$B a H_{2} < B e H_{2} < C a H_{2}$

Q. Among CaH2​,BeH2​,BaH2​, the order of ionic character is

BeH2​<BaH2​<CaH2​

CaH2​<BeH2​<BaH2​

BeH2​<CaH2​<BaH2​

BaH2​<BeH2​<CaH2​

Q. Among $C a H_{2}, B e H_{2}, B a H_{2}$ , the order of ionic character is

$B e H_{2} < B a H_{2} < C a H_{2}$

$C a H_{2} < B e H_{2} < B a H_{2}$

$B e H_{2} < C a H_{2} < B a H_{2}$

$B a H_{2} < B e H_{2} < C a H_{2}$