Diamond

Q. Choose the correct statment for graphite :

1. Each C atom in hexagonal ring make four sigma bonds with neighboring C atoms
2. Graphite is used as a dry lubricant
3. All of the above.
4. Electrons are immobile and localized over the whole sheet.

Q. Which of the following statement(s) is/are correct for diamond?

1. Used as an abrasive for sharpening hard tools.
2. It is used in making dyes.
3. It is used in the manufacture of tungsten filaments for electric light bulbs.
4. All of the above.

Q. Diamond, graphite, silicates are examples of :

1. Covalent solids
2. Ionic solids
3. Metallic solids
4. Molecular solids

Q. Why is diamond hardest substance on Earth?

1. Due to extended ionic bond formation
2. Due to extended covalent bond formation
3. Due to $s{p}^2$ hybridised carbons
4. Due to multiple $\pi$ bond formation.

Q. The $C-C$ bond length is maximum in

1. $\text{graphite}$
2. $C_{70}$
3. $C_{60}$
4. $\text{diamond}$

Q. With respect to graphite and diamond, which of the statement(s) given below is/are correct?

1. Graphite is harder than diamond
2. Graphite has higher electrical conductivity than diamond
3. Graphite has higher thermal conductivity than diamond
4. Graphite has higher $C-C$ bond order than diamond

Q. Correct statement(s) is/are:

1. Diamond has more thermal conductivity than graphite
2. 1 mol of $M{g}_2{C}_3$ reacts with water to give 3 mol of $C_3{H}_4$ gas
3. The order of the lewis acidic strength is: $B{F}_3>BC{l}_3>BB{r}_3$
4. Aqueous solution of borax is basic in nature