Silica

Q. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): $ICl$ is more reactive than $I_2$.
Reason (R): $ICl$ bond is weaker than $I-I$ bond.
In the light of the above statements, choose the most appropriate answer from the options given below:

1. Both (A) and (R) are correct but (R) is not the correct explanation of (A).
2. (A) is not correct but (R) is correct.
3. Both (A) and (R) are correct and (R) is the correct explanation of (A).
4. (A) is correct but (R) is not correct.

Q.

What happens when sulphur dioxide is dissolved in water?

Q. $HgC{l}_2\text{and}{I}_2$ both when dissolved in water containing $I^{-}$ ions the pair of species formed is :

1. $Hg{l}_2,I^{-}$
2. $Hg{I}_4^{2-},I_3^{-}$
3. $H{g}_2{I}_{2,}{I}^{-}$
4. $Hg{I}_2,I_3^{-}$

Q.

Which of the following is an amorphous solid ?

(a) Graphiter (C) (b) Quartz glass $\left(Si{O}_2\right)$

(c) Chrome alum (d) Silicon carbide (SiC)

Q. $Si{O}_2$ can react with:

1. $NaOH$ only
2. $HF$ only
3. Neither $HF$ nor $NaOH$
4. Both $HF$ and $NaOH$

Q.

What is the basic structural unit of silicates?

Q. The amorphous form of silica is:

1. Quartz
2. Kieselguhr
3. Cristobalite
4. Tridymite

Q. Which of the following is/are crystalline form(s) of silica?

1. Quartz
2. Cristobalite
3. Tridymite
4. Silica gel

Q. Choose the most appropriate answer from
$[S{O}_2,Si{O}_2,A{l}_2{O}_3,CO,MgO,N{a}_{2}O]$
(a) A covalent oxide of a metalloid.

Q.

If the starting material for the manufacture of silicones is RSiCl₃, write the structure of the product formed.

Q. Which one of the following is a correct set for $Si{O}_2$ ?

1. Linear
2. Tetrahedral
3. Angular
4. Trigonal planar

Q. Assertion: Saline hydrides are non-volatile, non-conducting and crystalline solids.
Reason: Saline hydrides are compounds of hydrogen with most of the p-block elements.

1. Both assertion and reason are true and reason is the correct explanation of assertion
2. Assertion is true but reason is false
3. Both assertion and reason are false
4. Both assertion and reason are true but reason is not the correct explanation of assertion

Q. Quartz is a crystalline variety of

1. Silica
2. Sodium silicate
3. SiC
4. Silicon

Q.

What is common between ${\mathrm{P}}_4{\mathrm{O}}_6$ and ${\mathrm{P}}_4{\mathrm{O}}_{10}$?

1. $s{p}^3$ hybridized

2. $\mathrm{P}-\mathrm{O}-\mathrm{P}$ bond

3. Acidic Oxide

4. All of these

Q.

Mortar is a mixture of

1. 1 part of slaked lime, 3 parts of sand and water

2. Limestone, sand and water

3. Dolomite, sand and water

4. Magnesite, slaked lime and water

Q.

The acid that can react with glass is ____________.

Q.

Name one metal hydroxide which is soluble and insoluble in sodium hydroxide.

Q.

Rhombic sulphur consists of which molecule?

1. S₂ molecule

2. S₈ molecule

3. S₆ molecule

4. S₄ molecule

Q. In CCP structure of compound XY, atom X is present at octahedral voids. The ratio of 6 th CN and 3th CN for an atom X located at body centre is

Q. The $NaCl$ structure can be converted into $CsCl$ structure by :

1. Application of high pressure
2. Passing it through a magnetic field
3. Application of low pressure
4. The conversion is not possible

Q.

A salt X, on heating releases CO₂ gas .If one molecule of this salt reacts with two molecules of HCl (acid), .calculate the number of metal atoms present in one molecule of X and determine the formula of X.

Q.

Name the gas obtained when rock salt reacts with conc. Sulphuric acid.

Q.

Different forms of silica such as quartz, tridymite and cristobalite are as follows:
Quartz $\stackrel{{870}^{\circ }C}{⟶}$ Tridymite $\stackrel{{1470}^{\circ }C}{\rightleftharpoons }$ Cristobalite

$\left(Si{O}_2\right)$ $\left(Si{O}_2\right)$ $\left(Si{O}_2\right)$

The structure possessed in them is:

1. Sheet silicate

2. Cyclic or ring silicate

3. Three-dimensional silicate

4. Chain silicate

Q.

Differentiate between acidic and basic oxides.

Q. The form of $Si{O}_2$ used as piezoelectric material:

1. Cristobalite
2. Quartz
3. Kiesulguhr
4. Silica gel

Q. Silica is soluble in

1. $HCl$
2. $HN{O}_3$
3. $H_{2}S{O}_4$
4. $HF$

Q.

State your observation, water is added to the product formed, when aluminium is burnt in a jar of nitrogen gas.

Q.

Why is${\mathrm{H}}_2{\mathrm{SO}}_4$ called sulfuric acid?

Q.

What is the chemical formula for Bromous acid?

Q.

Write the chemical name for dry ice. Justify its name and how it is stored.