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

The strongest factor responsible for reducing action of Li metal in an aqueous solution is :

1. Sublimation enthalpy .         

2. Ionisation enthalpy.

3. Hydration enthalpy .             

4. Electron-gain enthalpy.

The effect of addion of gypsum to cement is-

1. It reduces the setting time of cement .    

2. The setting time of cement increases.

3. The colour of cement becomes light .          

4. A shining surface is obtained.

A compound (A) is used in the preparation of washing soda to recover ammonia in Solvay's process. When CO₂ is bubbled through an aqueous solution of (A), the solution turns milky. It is used in whitewashing due to its disinfectant nature. The chemical formula of A is : 

1. $\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$                       

2. CaO

3. $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$                           

4. ${\mathrm{CaCO}}_3$

Which of the following statement about the sulphate of alkali metal is correct?

1. Expect $L{i}_{2}S{O}_4$ all sulphate of other alkali metals are soluble in hot water

2. All sulphate salts of alkali metals except lithium sulphate forms alum.

3. All sulphate salts of alkali metals except lithium sulphate do not decompose at high temperature 

4. All of the above

When a standard solution of NaOH is left in air for a few hours :

(1) a precipitate will form

(2) strength of solution will decrease

(3) the strength of solution will increase

(4) the concentration of $N{a}^{+}.$ion in solution will remains same

${\mathrm{CaCl}}_2$ is preferred over NaCl for clearing ice on roads particularly in very cold countries. This is because:

1. ${\mathrm{CaCl}}_2$ is less soluble in ${\mathrm{H}}_2\mathrm{O}$ than NaCl.

2. $CaC{l}_2$ is hygroscopic but NaCl is not.

3. Eutectic mixture of ${\mathrm{CaCl}}_2/{\mathrm{H}}_2\mathrm{O}$ freezes at $-55°C$ while that of $\mathrm{NaCl}/{\mathrm{H}}_2\mathrm{O}$ freezes at $-18°C$.

4. NaCl makes the road slippery but ${\mathrm{CaCl}}_2$ does not.

Which metal bicarbonates does not exist in solid state?

(i) $LiHC{O}_3$       (ii) $Ca{\left(HC{O}_3\right)}_2$     (iii) $Zn{\left(HC{O}_3\right)}_2$      (iv)$AgHC{O}_3$

(1) i,ii,iii,iv                           

(2) i,ii,iii

(3) i,ii,iv                               

(4) ii,iii,iv

The incorrect statement among the following is-

1. The milk of magnesia used as an antacid is chemically $\mathrm{MgO} + {\mathrm{MgCl}}_2$

2. Stability of alkali metal peroxides increases with an increase in atomic number.

3. Hydration energy of AgF is higher than its lattice energy.

4. Anhydrous ${\mathrm{MgCl}}_2$ cannot be prepared by direct heating of ${\mathrm{MgCl}}_2 . 6{\mathrm{H}}_2\mathrm{O}$. 

Calcium imide on hydrolysis gives gas (B) which on oxidation by bleaching powder gives gas (C). Gas (C) on reaction with magnesium give compound (D) which on hydrolysis gives again gas (B)> Identify (B), (C) and (D).

(1) $N{H}_3, N_2, M{g}_3{N}_2$ 

(2) $N_2, N{H}_3, MgNH$

(3) $N_2, N_2{O}_5, Mg{\left(N{O}_3\right)}_2$ 

(4)$N{H}_3 ,N{O}_2, Mg{\left(N{O}_2\right)}_2$