Allotropes of Carbon

Q. The one that is extensively used as a piezoelectric material is:

1. quartz
2. amorphous silica
3. mica
4. tridymite

Q.

Can a diamond conduct electricity$?$

Q. Which of the following is crystalline form of carbon?

1. Diamond

2. Graphite

3. Coke

4. Charcoal

Q.

A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.

Q. 46. The group of substances in which at melting point covalent bond becomes weak:- (1) NaCl, KCl, CaCl2 (2) I2(s), CH4(s), dry ice (3) B4C, diamond, SiC (4) All of the above

Q.

Explain briefly :

Graphite conducts electricity while diamond does not, although both are the forms of carbon.

Q.

In diamond each Carbon atom is covalently bonded to four others.

1. True
2. False

Q. Which of the following compounds is a meso compound?

1. 
2. 
3. 
4. 

Q. Which one of the following isotope of carbon is thermodynamically more stable ?

1. Buckminsterfullerene
2. Graphite
3. Diamond
4. None of the above

Q.

Which is harder graphite or diamond?

Q. Which of the following molecule has planar structure?

निम्नलिखित में से किस अणु की संरचना समतलीय है?

1. NH₃
2. CH₄
3. XeF₄
4. SF₄

Q. Describe the structure of the common form of ice.

Q.

A child accidentally drops a diamond in a charcoal fire. Will diamond change into a new form? Give reason.

Q. The hybridisation of carbon atoms in diamond and graphite are respectively:

1. $s{p}^3,s{p}^3$
2. $s{p}^2,s{p}^2$
3. $s{p}^2,s{p}^3$
4. $s{p}^3,s{p}^2$

Q. Which of the following statements is correct regarding $C_{60}$ fullerene?

1. It contains 12 six membered ring and 20 five membered ring.
2. It contains 20 six membered ring and 12 five membered rings
3. It consists of 25 six membered and 12 five membered rings.
4. It consists of 12 six membered and 25 five membered rings

Q. "Sodium does not form carbide, $N{a}_2{C}_2$ with carbon but $N{a}_2{C}_2$ can be formed when sodium reacts with acetylene."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Q. how to find Zeffective of Carbon

Q.

Which of the following noble gases finds use in cryogenics and very low-temperature refrigeration?

1. Helium

2. Neon

3. Argon

4. Krypton

Q. Assertion (A): Among IIIA group elements boron has highest melting point
Reason (R) : Boron exists as a giant covalent polymer :

1. Both A and R are true and R is not correct explanation of A
2. Both A and R are true and R is correct explanation of A
3. A is true but R is false
4. A is false but R is true.

Q. The reason for carbon to show allotropic forms is :

1. Catenation
2. $p\pi$-$p\pi$ bond formation.
3. $\sigma$-$\sigma$ bond formation.
4. (a) and (b) above.

Q.

Which of the following noble gases finds use in cryogenics and very low-temperature refrigeration?

1. Helium

2. Neon

3. Argon

4. Krypton