$\mathrm{RCl}$ $\underset{\mathrm{Si}}{\overset{\mathrm{cu}-\mathrm{powder}}{\to }}{\mathrm{R}}_2{\mathrm{SiCl}}_2\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }$
${\mathrm{R}}_2\mathrm{Si}{\left(\mathrm{OH}\right)}_2$ $\stackrel{\mathrm{condensation}}{\to }$ $\mathrm{A}$

Compound (A) is -

1.	A linear silicone	2.	A chlorosilane
3.	A linear silane	4.	A network silane

$\mathrm{B}{\left(\mathrm{OH}\right)}_3+\mathrm{NaOH}\rightleftharpoons {\mathrm{NaBO}}_2+\mathrm{Na}\left[\mathrm{B}{\left(\mathrm{OH}\right)}_4\right]+{\mathrm{H}}_2\mathrm{O}$

 This reaction is made to proceed in forward direction by -

1. Addition of Cis- 1,2 diol

2. Addition of borax

3. Addition of trans 1,2- diol

4. Addition of ${\mathrm{Na}}_2{\mathrm{HPO}}_4$

An Aqueous solution of borax reacts with 2 moles of acid due to -

1. Formation of 2 moles of  B(OH)₃  only

2. Formation of 2 moles of  [B(OH)₄]^-  only

3. Formation of 1 mole each of  B(OH)₃ and [B(OH)₄]^-

4. Formation of 2 moles each of [B(OH)₄]^- and B(OH)₃, only [B(OH)₄]^-  reacts with an acid 

Aluminium becomes passive in nitric acid because it-

1. Is a noble metal

2. Forms a thin film of oxide

3. Has a positive reduction potential

4.  None of the above

Chemically thermite is -

1.  Fe and Al

2.  Ferric oxide and aluminium powder

3.  Barium peroxide and magnesium powder

4.  Cu and aluminium

Borax bead test is responded by:

1.  Divalent metals

2.  Heavy metals

3.  Light metals

4.  Metal which forms coloured metaborates

The incorrect statement among the following is -

1. $\mathrm{Ge}{\left(\mathrm{OH}\right)}_2$ is amphoteric

2. ${\mathrm{GeCl}}_2$ is more stable than ${\mathrm{GeCl}}_4$

3. ${\mathrm{GeO}}_2$ is weakly acidic

4. GeCl₄ + 2HCl ⇄ H₂[GeCl₆]

Silicon carbide is used as:

${\mathrm{R}}_3\mathrm{SiCl}$ 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.

The percentage of lead in a lead pencil is-

1.  20

2.  0

3.  80

4.  70