Q: The structure of \$SiO_{2}\$ ?

Si in Silica is \$sp_3\$ hybridised giving it a tetrahedral structure.

Q: Silicones are:

Explanation Silicones belong to the organo-silicon polymer family since they are comprised entirely of carbon, silicon, and oxygen atoms. these elements are naturally occurring and safe. Due to the presence of alkyl groups on silicon atoms, silicones are hydrophobic in nature. They have strong dielectric strength and thermal stability in general. They are oxidation-resistant. They are commonly employed in waterproofing sealants, insulators, greases, and textiles because of their qualities. They're also biocompatible. They're also found in surgical plants. Thus, the low reactivity with chemicals and inertness towards it makes silicones a non-toxic one. Henceforth, the correct answer is option B.

Q: In silicones, silicon is strongly linked to:

\$ Si-O-Si-O-Si \$ bonds are found in silicones.

Q: Which is the crystalline form of silica?

Silica (\$SiO_2\$) occurs in various crystallographic forms such as quartz, crystobalite and tridymite that are interconvertible at suitable temperatures.

Question 1

Silica is heated with carbon in electric furnace to form :

Accepted Answer

When quartz or sand are heated with an excess of coke in an electric arc furnace at $2000-2500$$^{o}$C silicon carbide or carborundum is formed.$SiO_2 + 3C \rightarrow SiC +2CO$

Question 2

Quartz is the form ?

Accepted Answer

Silica is found in many crystalline and amorphous forms . Quartz is a crystalline form of silica.

Question 3

The structure of $SiO_{2}$ ?

Accepted Answer

Si in Silica is $sp_3$ hybridised giving it a tetrahedral structure.

Question 4

Which of the following is used for making opticalinstruments :

Accepted Answer

Silica is an important ingredient in making glass, which is extensively used in making optical devices.

Question 5

Density is highest for :

Accepted Answer

Explanation:The density of elements increases as we move from top to bottom in a group.&#10;&#10;In group 14 elements, as we move from $C$ to $Pb$&#10;the number of orbits increases.&#10;&#10;So the size of the atom increases and its density also&#10;increases.&#10;&#10;Thus $Pb$ has the highest density.&#10;&#10;Final Answer: Correct option (D).

Question 6

Silicones are:

Accepted Answer

Explanation&#10;&#10;Silicones belong&#10;to the organo-silicon polymer family since they are comprised entirely of&#10;carbon, silicon, and oxygen atoms. these elements are naturally occurring and safe.&#10;&#10;Due to the presence of alkyl groups on silicon&#10;atoms, silicones are hydrophobic in nature. They have strong dielectric&#10;strength and thermal stability in general. They are oxidation-resistant. &#10;&#10;They are commonly&#10;employed in waterproofing sealants, insulators, greases, and textiles because of&#10;their qualities. They're also biocompatible. They're also found in surgical&#10;plants.&#10;&#10;Thus, the low reactivity with chemicals and inertness towards it makes silicones a non-toxic one.&#10;&#10;Henceforth, the correct answer is option B.

Question 7

Silica dissolves in NaOH solution to form:

Accepted Answer

Silica is almost non-reactive due to the presence of very strong Si-C bonds. They are unaffected by dihydrogen, halogen and acids except $HF$ and $NaOH$ to form $SiF_4$ and $Na_2SiO_3$ respectively. The reaction is as follow:$SiO_{2} + 2NaOH \rightarrow Na_{2}SiO_{3} +H_{2}O$

Question 8

In silicones, silicon is strongly linked to:

Accepted Answer

$ Si-O-Si-O-Si $       bonds are found in silicones.

Question 9

Which is the crystalline form of silica?

Accepted Answer

Silica ($SiO_2$) occurs in various crystallographic forms such as quartz, crystobalite and tridymite that are interconvertible at suitable temperatures.

Question 10

Rock crystal is:

Accepted Answer

All clear colourless quartzs are known as rock crystal and they are used as ornamental stone.

Some P Block Elements

Chemistry
4617 Views

Silica is heated with carbon in electric furnace to form :

Quartz is the form ?

The structure of $S i O_{2}$ ?

Which of the following is used for making optical
instruments :

Density is highest for :

Silicones are:

Silica dissolves in NaOH solution to form:

In silicones, silicon is strongly linked to:

Which is the crystalline form of silica?

Rock crystal is:

Some P Block Elements

Chemistry 4617 Views

Silica is heated with carbon in electric furnace to form :

Quartz is the form ?

The structure of SiO2​ ?

Which of the following is used for making optical instruments :

Density is highest for :

Silicones are:

Silica dissolves in NaOH solution to form:

In silicones, silicon is strongly linked to:

Which is the crystalline form of silica?

Rock crystal is:

Chemistry
4617 Views

The structure of $S i O_{2}$ ?

Which of the following is used for making optical
instruments :