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Write the uses of silicon dioxide in chemical industry.

Important Questions on The p-Block Elements

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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon

Correct statements among regarding silicones are:
(a) They are polymers with hydrophobic character.
(b) They are biocompatible.
(c) In general, they have high thermal stability and low dielectric strength.
(d) Usually, they are resistant to oxidation and used as greases.

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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
The gas evolved on heating CaF2 and SiO2 with concentrated H2SO4, on hydrolysis gives a white gelatinous precipitate. The precipitate is:
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Dry ice is
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Zeolites are shape selective structures because of
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Identify the correct statements from the following:
(a) CO2g is used as a refrigerant for ice cream and frozen food.
(b) The structure of C60 contains twelve six-membered carbon rings and twenty-five membered carbon rings.
(c) ZSM−5, a type of zeolite, is used to convert alcohols into gasoline.
(d) CO is a colourless and odourless gas.
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Identify the incorrect statements from the following
I. Tin in +2 state acts as reducing agent while lead in +4 state acts as strong oxidising agent.
II. Silicon exists as both SiF62- and SiCl62- forms.
III. The hybridisation of carbon in fullerene is sp3.
IV. Among Ge, Sn and Pb lowest melting point is for Sn.
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
SiO2 is attacked by which one/ones of the following?
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags.

Reason (R): Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning.

In the light of the above statements, choose the correct answer from the options given below:

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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
The correct statement about silicone is
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Si reacts with CH3Cl at 573 K in the presence of Cu powder to form methyl substituted chlorosilanes. Among the given methyl substituted chlorosilanes, whose yield is minimum?
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
The basic structural unit of feldspar, zeolites mica, and asbestos is:
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon

What would be the products for the following reactions respectively? (water molecules would be the expected biproduct)

(i) SiO2+2NaOH→?

(ii) SiO2+4HF→?

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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
CO2 is a gas, while SiO2 is a solid, but both are
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
In silicon dioxide: 
HARD
Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Write structure of SiO2.
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Explain the structure of silica.
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Identify B in the following reaction,

H4SiO4→   1000℃   -H2OA→    Carbon   ∆B+CO
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Quartz is a crystalline variety of:
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon
Why SiO2 does not dissolve in water?
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Chemistry>Inorganic Chemistry>The p-Block Elements>Some Important Compounds of Carbon and Silicon

Explain the structure of silica. How does it react with a. NaOH and b. HF.