Carbon dioxide is a gas but silica is a solid because:

1.  carbon dioxide is composed of discrete covalent ${\mathrm{CO}}_2$ molecules whereas silica has continuous

     tetrahedral structure

2.  ${\mathrm{CO}}_2$ molecules are lighter than ${\mathrm{SiO}}_2$ molecules

3.  ${\mathrm{CO}}_2$ is more acidic than ${\mathrm{SiO}}_2$

4.  melting point of silica is very high

The greatest percentage of $\mathrm{CO}$ is in:

1.  coal gas

2.  producer gas

3.  water gas

4.  oil gas

Which of the following shows bond in silicone?

1.  $\mathrm{Si}—\mathrm{C}—\mathrm{Si}—\mathrm{O}—\mathrm{Si}$

2.  $\mathrm{Si}—\mathrm{C}—\mathrm{Si}—\mathrm{C}—\mathrm{Si}$

3.  $—\stackrel{\mathbf{|}}{\mathrm{Si}}—\mathrm{O}—\stackrel{\mathbf{|}}{\mathrm{Si}}—\mathrm{O}—\stackrel{\mathbf{|}}{\mathrm{Si}}—$

4.  $\mathrm{Si}—\mathrm{Si}—\mathrm{Si}—\mathrm{Si}$

Mica is chemically:

1.  potassium alumino silicate having sheet structure

2.  calcium alumino silicate having fibrous structure

3.  calcium magnesium silicate having three dimensional network

4.  hydrated sodium alumino silicate having three dimensional network

Silicon carbide is used as:

$\mathrm{CO}$ reacts with chlorine in presence of sunlight to give:

1.  ${\mathrm{COCl}}_2$

2.  ${\mathrm{CO}}_2$

3.  ${\mathrm{CCl}}_4$

4.  ${\mathrm{CHCl}}_3$

Litharge is:

1. $\mathrm{PbO}$

2. ${\mathrm{PbO}}_2$

3. ${\mathrm{Pb}}_3{\mathrm{O}}_4$

4. $\mathrm{Pb}{\left({\mathrm{CH}}_3\mathrm{COO}\right)}_2$

Red lead is:

1.  $\mathrm{PbO}$

2.  ${{\mathrm{Pb}}_3\mathrm{O}}_4$

3.  ${\mathrm{PbO}}_2$

4.  $\mathrm{HgS}$

White lead or basic lead carbonate is:

1.  $\mathrm{Pb}{\left(\mathrm{OH}\right)}_2·2{\mathrm{PbCO}}_3$

2.  $\mathrm{Pb}{\left(\mathrm{OH}\right)}_2·\mathrm{Pb}{\left({\mathrm{CH}}_3\mathrm{COO}\right)}_2$

3.  ${\mathrm{PbCO}}_3$

4.  ${\mathrm{PbCO}}_3·\mathrm{Pb}{\left(\mathrm{OH}\right)}_2$

${\mathrm{R}}_3\mathrm{SiCl}$ on complete hydrolysis forms:

1.  ${\mathrm{R}}_3\mathrm{SiOH}$

2.  ${\mathrm{R}}_3\mathrm{Si}—\mathrm{O}—{\mathrm{SiR}}_3$

3.  ${\mathrm{R}}_3\mathrm{Si}=\mathrm{O}$

4.  None of the above.