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 ${\mathrm{B}}_2{\mathrm{Cl}}_4$

Tin dissolves in concentrated and dil. ${\mathrm{H}}_2{\mathrm{SO}}_4$ as well as ${\mathrm{HNO}}_3$ at temp 150 degree celcius.Which of the following is not the exact product of this process?

1.  ${\mathrm{SnSO}}_4$

2.  $\mathrm{Sn}{\left({\mathrm{SO}}_4\right)}_2$

3.  $\mathrm{Sn}{\left({\mathrm{NO}}_3\right)}_3$

4.  ${\mathrm{H}}_2{\mathrm{SnO}}_3$  

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.  ${\mathrm{H}}_2{\mathrm{BO}}_3$

Mellitic acid formed by the oxidation of graphite with 

1.  Chromic acid

2.  Alkaline ${\mathrm{KMnO}}_4$/heat

3.  Fuming ${\mathrm{HNO}}_3$

4.  dil. ${\mathrm{HNO}}_3$

Incorrect option about 2-D sheet silicates is

1. Two O-atoms of each tetrahedra are shared

2. General formula is ${\left({\mathrm{Si}}_2{\mathrm{O}}_5\right)}_{\mathrm{n}}^{2\mathrm{n}-}$

3. Co-ordination number of Si is 4

4. Number of O-atoms per tetrahedra unit is $\frac{5}{2}$

The correct formula of colemanite mineral is:

1.  ${\mathrm{Ca}}_2{\mathrm{B}}_6{\mathrm{O}}_{11}5{\mathrm{H}}_2\mathrm{O}$

2.  ${\mathrm{CaB}}_4{\mathrm{O}}_7.{\mathrm{NaBO}}_{2}8{\mathrm{H}}_2\mathrm{O}$

3.  $2{\mathrm{Mg}}_3{\mathrm{B}}_8{\mathrm{O}}_{15}{\mathrm{MgCl}}_2$

4.  ${\mathrm{Ca}}_2{\mathrm{B}}_6{\mathrm{O}}_{11}.3{\mathrm{H}}_2\mathrm{O}$

Hydrolysis of ${\mathrm{SiF}}_4$ gives a compound, in which maximum coordination number of Si is

1.  6

2.  4

3.  8

4.  7