The incorrect statement among the following is -

1. ${\mathrm{PbX}}_2$ is more stable than ${\mathrm{PbX}}_4$

2. ${\mathrm{PbCl}}_4$ is less stable than ${\mathrm{SnCl}}_4$ but ${\mathrm{PbCl}}_2$ is more stable than ${\mathrm{SnCl}}_2$

3. ${\mathrm{PbCl}}_4$ is less stable than ${\mathrm{SnCl}}_4$

4. Pb(II) is a good reducing agent while Sn(II) is not

Boric acid on heating at $150°\mathrm{C}$ gives:

1. ${\mathrm{B}}_2{\mathrm{O}}_3$

2. ${\mathrm{H}}_2{\mathrm{B}}_4{\mathrm{O}}_7$

3. ${\mathrm{HBO}}_2$

4. ${\mathrm{H}}_2{\mathrm{BO}}_3$

Orthoboric acid when heated to red hot gives-

The main factor responsible for weak acidic nature of  B-F bonds in $B{F}_3$ is:

(1) large electronegativity of F

(2) three centred two electrons bonds in $B{F}_3$

(3) px-$d\mathrm{\pi }$ back bonding

(4) $p\mathrm{\pi }-\mathrm{p\pi }$ back bonding 

 Which among the following is a gas?

1. $B{F}_3$

2. $BC{l}_3$

3. $BB{r}_3$

4. $B{I}_3$

CO₂ and N₂ are non-supporters of combustion. However, for putting out fires CO₂ is preferred over N₂ because CO₂:

1. Does not burn.

2. Forms non-combustible products with burning substances.

3. Is denser than nitrogen.

4. Is a more reactive gas.

$CC{l}_4$ does not show hydrolysis but $SiC{l}_4$ is readily hydrolysed because:

(1) carbon cannot expand its octet but silicon can expand.

(2) electronegativity of carbon is higher than of silicon

(3) IP of carbon is higher than of silicon

(4) carbon forms double and triple bonds but not silicon

Quartz is made of silicon and oxygen joined in a network arrangement that is similar to:

1. Diamond

2. Graphite

3. $O_2$

4. None of the above

$R_{3}SiCl$ on polymerisation after hydrolysis forms:

(1) $R_{3}SiOH$

(2) $R_{3}Si-O-Si{R}_3$

(3) $R_{2}Si=O$

(4) None of these

The basic reaction involved in the synthesis of linear silicones is:

(1) the hydrolysis of trimethyl chlorosilane

(2) the hydrolysis of dimethyl dichlorosilane

(3) the hydrolysis of ethyl chlorosilane

(4) the acid hydrolysis of dimethyl silane