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

Which of the following order is correct?

1. $K^{+}<C{a}^{2+}<p^{3-}<S^{2-}$: Ionic size

2. $N{a}_{\left(aq.\right)}^{+}>K_{\left(aq.\right)}^{+}>R{b}_{\left(aq.\right)}^{+}>C{s}_{\left(aq.\right)}^{+}$: Electrical conductance

3. $A{l}_{\left(aq.\right)}^{3+}>M{g}_{\left(aq.\right)}^{2+}>N{a}_{\left(aq.\right)}^{+}$: Hydrated size

4. $I_{\left(aq.\right)}^{-}<B{r}_{\left(aq.\right)}^{-}<C{l}_{\left(aq.\right)}^{-}<F_{\left(aq.\right)}^{-}$: Ionic mobility

Compound having lowest melting point:

(1) LiCl                               

(2) CsCl

(3) RbCl                               

(4) KCl

Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.

$\left(\mathrm{I}\right) \mathrm{Numbers} \mathrm{of} \mathrm{S}—\mathrm{S} \mathrm{bonds} \mathrm{in} {\mathrm{H}}_2{\mathrm{S}}_{\mathrm{n}}{\mathrm{O}}_6 \mathrm{are} (\mathrm{n}+1)$
$\left(\mathrm{II}\right) \mathrm{When} {\mathrm{F}}_2 \mathrm{reacts} \mathrm{with} \mathrm{water} \mathrm{gives} \mathrm{HF}, {\mathrm{O}}_2 \mathrm{and} {\mathrm{O}}_3$
$\left(\mathrm{III}\right) {\mathrm{LiNO}}_3 \mathrm{and} {\mathrm{BaCl}}_2 \mathrm{compounds} \mathrm{are} \mathrm{used} \mathrm{in} \mathrm{fire} \mathrm{works}$
$\left(\mathrm{IV}\right) \mathrm{Be} \mathrm{and} \mathrm{Mg} \mathrm{are} \mathrm{ionic} \mathrm{and} \mathrm{polymeric}$
$$
$\left(\mathrm{a}\right)\hspace{0.17em}\mathrm{FTTF} \left(\mathrm{b}\right) \mathrm{FTTT} \left(\mathrm{c}\right) \mathrm{TFTT} \left(\mathrm{d}\right) \mathrm{TTFF}$

Which of the following statements is true for all the alkali metals?

(1) Their nitrate decomposes on heating to give the corresponding nitrites and oxygen.

(2) Their chlorides are deliquescent and crystallize as hydrates.

(3) They react with water to form hydroxide and hydrogen.

(4) They readily react with halogens to form ionic halides. ${\mathrm{M}}^{+}{\mathrm{X}}^{-}.$

Which of the following statements is not true about the dilute solutions of alkali metals in liquid ammonia?

1. They are deep blue coloured solutions.

2. They are highly conducting in nature.

3. They are diamagnetic in nature.

4. Ammoniated cations and ammoniated anions are formed in a solution.

Which is not correctly matched?

(1) Basic strength of oxides                                 ${\mathrm{Cs}}_2\mathrm{O}<{\mathrm{Rb}}_2\mathrm{O}<{\mathrm{K}}_2\mathrm{O}<{\mathrm{Na}}_2\mathrm{O}<{\mathrm{LiO}}_2$

(2) Stability of peroxides                                      ${\mathrm{Na}}_2\mathrm{O} <{\mathrm{K}}_2{\mathrm{O}}_2<{\mathrm{Rb}}_2{\mathrm{O}}_2<{\mathrm{Cs}}_2{\mathrm{O}}_2$

(3) Stability of bicarbonate                                   ${\mathrm{LiHCO}}_3<{\mathrm{NaHCO}}_3<{\mathrm{KHCO}}_3<{\mathrm{RbHCO}}_3<\mathrm{Cs} {\mathrm{HCO}}_3$

(4) Melting Point                                                  $\mathrm{NaF}<\mathrm{NaCl}<\mathrm{NaBr}<\mathrm{Nal}$

(A) 1 and 4                                           

(B) 1 and 3

(C) 1 and 2                                           

(D) 2 and 3