The chain length of silicones can be controlled by adding:
1.  \(\mathrm{CH_3SiCl_3}\)
2.  \(\mathrm{SiCl_4}\)
3.  \(\mathrm{(CH_3)_2SiCl_2}\)
4.  \(\mathrm{(CH_3)_3SiCl}\)

Identify the correct statements among the following:

a. ${\mathrm{CO}}_2\left(\mathrm{g}\right)$ is used as a refrigerant for ice-cream and frozen food.

b. The structure of ${\mathrm{C}}_{60}$ contains twelve six-carbon rings and twenty five-carbon rings.

c. ZSM-5, a type of zeolite, is used to convert alcohol into gasoline.

d. CO is a colourless and odourless gas

1. (a) and (c) only

2. (b) and (c) only

3. (c) and (d) only

4. (a), (b) and (c) only

Match the allotropes of cabon given in List I with the respective characteristics given in List II.

The reason behind carbon showing catenation property but lead does not is:

1. Due to the smaller size of C than that of Pb

2. Due to the smaller size of Pb than that of C

3. Due to the smaller ionization energy of C than that of Pb

4. Due to the inert pair effect

Boric acid is polymeric due to-

1. Its acidic nature.

2. The presence of hydrogen bonds.

3. Its monobasic nature.

4. Its geometry.

In diborane, the two H-B-H angles are nearly-

1. $60°,$ $120°$

2. $97°,120°$

3. $97°,150°$

4. $120°,$ $180°$

The basic structural unit of silicates is:

1. SiO₄^4–

2. SiO₃^2–

3. SiO₄^2–

4. SiO

${\mathrm{H}}_3{\mathrm{BO}}_3$ is -

1. A Monobasic acid and a weak Lewis acid.

2. A Monobasic and a weak Bronsted acid..

3. A Monobasic and a strong Lewis acid.

4. A Tribasic and a weak Bronsted acid.