Silica

Q.

In silicon dioxide:

1. Silicon is bonded to two silicon atoms.

2. Each silicon atom is surrounded by two oxygen atoms and each oxygen atom is bonded to two silicon atoms.

3. There are double bonds between silicon and oxygen atoms.

4. Each silicon atom is surrounded by four oxygen atoms and each oxygen atom is bonded to two silicon atoms.

Q.

$C(OH{)}_4$ is unstable because a carbon atom cannot hold more than one -OH groups but $Si(OH{)}_4$ is a stable compound because

1. C-O bond energy is low

2. C-O bond energy is high

3. Si-O bond energy is low

4. Si-O bond length is small

Q.

Silicon dioxide is formed by the reaction of

1. 

2. 

3. 

4. 

Q.

The basic structure of silicate is:-

1. 

2. 

3. 

4. 

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.

The composition of the common glass is

1. $N{a}_{2}O.CaO.6Si{O}_2$

2. $CaO.A{l}_2{O}_3.Si{O}_2$

3. $N{a}_{2}O.A{l}_2{O}_3.Si{O}_2$

4. $N{a}_{2}O.CaO.6Si{O}_2$

Q.

Shape of $C{O}_2$& $Si{O}_2$ respectively are

1. Linear & tetrahedral

2. Linear & angular

3. Angular & tetrahedral

4. Linear & linear

Q.

Which of the following is known as carborundum?

1. 

2. 

3. 

4. 

Q.

A when added to silica gives B. A and B are:

1. 

2. 

3. 

4. 

Q.

$Si{O}_2$ reacts with:

1. $N{a}_{2}C{O}_3$

2. $C{O}_2$

3. $HF$

4. $HCl$