Borax bead test is responded by:

1.  divalent metals

2.  heavy metals

3.  light metals

4.  metal which forms coloured metaborates

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 a 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. The melting point of silica is very high.

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

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

1.  ${\mathrm{COCl}}_2$

2.  ${\mathrm{CO}}_2$

3.  ${\mathrm{CCl}}_4$

4.  ${\mathrm{CHCl}}_3$

Butter of tin is:

1.  ${\mathrm{SnCl}}_2·5{\mathrm{H}}_2\mathrm{O}$

2.  ${\mathrm{SnCl}}_4·5{\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{SnBr}}_2·2{\mathrm{H}}_2\mathrm{O}$

4.  ${\mathrm{SnBr}}_4·5{\mathrm{H}}_2\mathrm{O}$

Ordinary glass is:

1. Sodium silicate

2. Copper silicate

3. Calcium silicate

4. A mixture of calcium and sodium silicates with silica

The substance used to impart green colour to glass is:

1.  ${\mathrm{Cu}}_2\mathrm{O}$

2.  $\mathrm{CdS}$

3.  ${\mathrm{MnO}}_2$

4.  ${\mathrm{Cr}}_2{\mathrm{O}}_3$

Carbogen is:

1.  A mixture of ${\mathrm{O}}_2+5-10\% of {\mathrm{CO}}_2$.

2.  Used by pneumonia patients for respiration.

3.  Used by victims of $\mathrm{CO}$ for respiration.

4.  All of the above.

Death due to gunshot is caused by poisoning of:

1.  Hg

2.  Pb

3.  Fe

4.  As

Consider the following reaction

${\mathrm{BF}}_3 \stackrel{{\mathrm{Al}}_2{\mathrm{Cl}}_4}{\to } \left(\mathrm{A}\right) \underset{\mathrm{discharged}}{\overset{{\mathrm{H}}_2 - \mathrm{gas}}{\to }} \left(\mathrm{B}\right) \stackrel{{\mathrm{H}}_2\mathrm{O}}{\to } \left(\mathrm{C}\right)$

The correct statement among the following is -

1. (A) is ${\mathrm{BCl}}_3$

2. (C) is ${\mathrm{B}}_2{\mathrm{H}}_6$

3. (C) is ${\left[{\mathrm{B}}_2{\left(\mathrm{OH}\right)}_4\right]}^{-}$

4. (B) is ${\mathrm{B}}_2{\mathrm{Cl}}_4$