Incorrect statement among the following is: 

1.	Quartz is extensively used as a piezoelectric material.
2.	Silicones are a group of organosilicon polymers, which have (-R2SiO-) as a repeating unit.
3.	Basic structural unit in silicates is the SiO44– tetrahedron.
4.	Feldspars are not aluminosilicates.

Which of the following statements is incorrect?

Which of the following oxide is amphoteric?

1. CO₂ 

2. SnO₂

3. CaO 

4. SiO₂

Al₂O₃ can be converted to anhydrous AlCl₃ by heating:

1. $A{l}_2{O}_3$ $with$ $HCl$ $gas$

2. $A{l}_2{O}_3$ $$with NaCl in solid-state

3. a mixture of $A{l}_2{O}_3$ $$ and carbon in dry $C{l}_2$ gas

4. $A{l}_2{O}_3$ $$ with $C{l}_2$ gas

Which one of the following anions is present in the chain structure silicates?

1. $S{i}_2{O}_7^{6-}$

2. $\left(S{i}_2{O}_5^{2-}\right)n$

3. $\left(Si{O}_3^{2-}\right)n$

4. $Si{O}_4^{4-}$

A compound among the following that is least likely to behave as a Lewis base is:

The basic structural unit of silicates is:

1. SiO₄^4–

2. SiO₃^2–

3. SiO₄^2–

4. SiO

Which of these is not a monomer for a high molecular mass silicone polymer?

A compound among the following having a similar structure to graphite is:

1. B
2. B₄C
3. B₂H₆
4. BN