Uses of Group 14 Elements

${\mathrm{BF}}_3$ is planar and electron deficient compound. Hybridization and number of electrons around the central atom, respectively are:

Being highly porous, activated charcoal is used in adsorbing _____ gases.

Graphite fibers embedded in _____ material form high strength, lightweight composites.

Identify the correct statements from 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-membered carbon rings and twenty-five membered carbon rings.
(c) $\mathrm{ZSM}-5$, a type of zeolite, is used to convert alcohols into gasoline.
(d) $\mathrm{CO}$ is a colourless and odourless gas.

Which of the following structural features of graphite best accounts for its use as a lubricant?

Assertion: Zeolite, which is hydrated sodium aluminium silicate is used as water softner.
Reason : The sodium ions of zeolite are exchanged with calcium and magnesium ions when hard Water is passed through it.

Assertion: Silicones are hydrophobic and used for water proofing of fabrics.
Reason : Silicones having being surrounded by non-polar alkyl groups are water repelling in nature.

Portland cement is an important building material and a mixture of oxides of several elements. The oxides of gr $13$ and gr $14$ present in the mixture are:

Which is an incorrect match for the use of ${SiO}_2$?

Zeolites are extensively used in -

What is the chief constituent of pyrex glass?

The composition of the common glass is

Which of the following does not have a lone pair on the central atom?

In laboratory silicon can be prepared by the reaction

Which of the following does not contains silicon ?

Clay is an example of

Which kind of attractive forces are likely to be holding particles together in a substance that melts at $681 °\mathrm{C}$ and that conducts electricity when molten but not when solid?

Which one of the following statements about the zeolite is false?

Glass is a