Arrange in the increasing order according to the given properties and explain the order: (i) MgCl_(2),AlCl_(3),NaCl,SiCl_(4) (melting point), (ii) LiBr, NaBr,KB r (melting point), (iii) MgCO_(3),CaCO_(3),BeCO_(3) (thermal stability), (iv) HgI_(2),HgCl_(2) (intensity of colour).

Arrange in the increasing order according to the given properties and

1.	Arrange in the increasing order according to the given properties and explain the order: (i) MgCl_(2),AlCl_(3),NaCl,SiCl_(4) (melting point), (ii) LiBr, NaBr,KB r (melting point), (iii) MgCO_(3),CaCO_(3),BeCO_(3) (thermal stability), (iv) HgI_(2),HgCl_(2) (intensity of colour).
Answer» Solution :(i) `SiCl_(4) lt AlCl_(3) lt MgCl_(2) lt NaCl` : [Ionic potential incrases with EITHER INCREASE to charge on cation or cationic radius. As a result, covalent character and melting point of the compounds formed increases.] (ii) The order of melting point of the given bromides should be `LiBr lt NABR lt Kb r`. due to increase in the size of cation from `Li^(+)` to `K^(+)`, the value of a `phi` increases. so, covalent character of the compounds increases. however, due to DECRESE in LATTICE enthalpy from NaBr to Kbr, the melting point decreases. therefore the correct order of melting point is `LiBr lt NaBr gt KBr`. (iii) N/A