In the case of alkali metals, the covalent character decreases in the order

1. MCl>MI>MBr>MF

2. MF>MCl>MBr>MI

3. MF>MCl>MI>MBr

4. MI>MBr>MCl>MF

The thermal stability of these hydrides decreases in which of the following orders?

(1) CsH > RbH > KH > NaH > LiH

(2) KH > NaH > LiH > CsH > RbH

(3) NaH > LiH > KH > RbH > CsH

(4) LiH > NaH > KH > RbH > CsH

Which of the following compounds has a positive enthalpy of solution?

(1) LiF                                       

 (2) LiCl

(3) LiBr                                       

(4) Lil

Property of the alkaline earth metals that increases with their atomic number is -

1. Solubility of their hydroxides in water.

2. Solubility of their sulphates in water.

3. Ionisation energy.

4. Electronegativity.

An alkaline earth metal sulphate that has hydration enthalpy higher than the lattice enthalpy is -

1. CaSO₄               

2. BeSO₄

3. BaSO₄               

4. SrSO₄

An active ingredient in bleaching powder for bleaching action is -

1. Ca(OCl)₂             

2. CaO₂Cl

3. CaCl₂                 

4. CaOCl₂

Which of the following metal on burning in moist air does not give the smell of ammonia?

1. Mg                               

2. Ca

3. K                                 

4. Li

Among the carbonates of alkali metals which one has highest thermal stability?

(1) $C{s}_{2}C{O}_3$                 

(2) $R{b}_{2}C{O}_3$                     

(3) $K_{2}C{O}_3$                   

(4) $N{a}_{2}C{O}_3$

Incorrect statement is:

(a)$NaHC{O}_3$ and $KHC{O}_3$ have same crystal structure

(b) On heating $LiN{O}_3$ decomposes into $L{i}_{2}O$ and $N{O}_2$

(c) Among alkali metals, Li metal impart red colour to flame 

(d) $L{i}_{2}S{O}_4$ does not form alum 

The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to:

(1) Ionic nature of lithium fluoride             

(2) High lattice enthalpy

(3) High hydration enthalpy of lithium ion

(4) Low ionisation enthalpy of lithium atom