Tag: organic compounds

Questions Related to organic compounds

Which of the following statements is/are incorrect for diamond?
(a) The refractive index of diamond is highest among solids.
(b) Diamond is hard because all the valence electrons of each carbon atom are involved in bond formation.
(c) Diamond is thermodynamically more stable than graphite.
(d) One carat of diamond represents its weight.

chemistry occurrence of carbon compounds in nature organic compounds allotropes of carbon versatile nature of carbon

  1. All are correct

  2. a, b and c

  3. a and b

  4. c only

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Correct Option: D
Explanation:

Graphite is thermodynamically more stable than diamond, diamond is kinetically stable thus statement c is incorrect. 


Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the same weight as a paperclip. Carat is just a unit to represent its weight. 


Diamond also possess an extremely high refractive index and fairly high dispersion. 

Hence, the answer is option $\text{D}$

Carbon in __________ form conducts electricity.

chemistry occurrence of carbon compounds in nature organic compounds allotropes of carbon versatile nature of carbon

  1. diamond

  2. graphite

  3. coal

  4. petroleum

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Correct Option: B
Explanation:

Graphite is an allotrope of carbon. It is an electrical conductor due to vast electron delocalisation within the layers. These are mobile electrons hence responsible for electrical conduction.

The carbon atoms in diamond are bonded to each other by:

chemistry occurrence of carbon compounds in nature organic compounds allotropes of carbon versatile nature of carbon

  1. ionic bond

  2. coordinate bond

  3. hydrogen bonds

  4. covalent bonds

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Correct Option: D
Explanation:

The bonds between carbon atoms in diamond are covalent because covalent bonding is the only option when only nonmetals are present.

The rigid network of carbon atoms, held together by strong covalent bonds, makes diamond very hard. This makes it useful for cutting tools, such as diamond-tipped glass cutters and oil rig drills.

Fullerene, an allotrope of carbon, has 60 carbon atoms joined together and no other element in it. There are various types of fullerenes. $C _{60}, C _{70}, C _{74}$ and $C _{78}$ are the members of the fullerene family. Identify the property due to which such large numbers of carbon atoms are joined together in this molecule :

chemistry allotropy of carbon organic compounds allotropes of carbon versatile nature of carbon

  1. Isomerism

  2. Homologous

  3. Catenation

  4. Metamerism

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Correct Option: C
Explanation:

Catenation is a self-linking property which is maximum present in carbon, because of this property large number of carbon atoms joined together to form molecule.

Which of the following is not an allotrope of carbon?

chemistry occurrence of carbon compounds in nature organic compounds allotropes of carbon versatile nature of carbon

  1. Buckyballs

  2. diamond

  3. graphite

  4. carbon dioxide

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Correct Option: D
Explanation:

Buckyballs, diamond and graphite are allotrops of carbon while carbon dioxide is a compound of carbon.

Which of the following is not an allotropic form of carbon?

chemistry occurrence of carbon compounds in nature organic compounds allotropes of carbon versatile nature of carbon

  1. Fluorine

  2. Fullerene

  3. Diamond

  4. Graphite

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Correct Option: A
Explanation:

Fullerene, graphite and diamond all are different allotrops of carbon.

Fluorine is an entirely different element, whose atomic number is $9$.
Option A is the correct answer.
Fluorine is not an allotrope of carbon.

Carbon forms bonds with another element by :

chemistry carbon compounds organic compounds allotropes of carbon versatile nature of carbon

  1. transferring of electrons.

  2. sharing of electrons.

  3. Both A and B.

  4. None of the above.

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Correct Option: B
Explanation:

Carbon shares electrons while making compounds. It do not transfers electrons to other ions.


Hence, the correct option is $B$.


Which of the following is the true statement for carbon atoms :

chemistry carbon compounds organic compounds allotropes of carbon versatile nature of carbon

  1. A carbon atom loses $4$ electrons.

  2. A carbon atom forms $4$ covalent bonds.

  3. A carbon atom share the $2$ electrons in the first principal energy level.

  4. A carbon atom gains $4$ electrons.

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Correct Option: B
Explanation:

Carbon atoms form 4 covalent bonds. Carbon (atomic number 6) has electronic configuration $\displaystyle 1s^2 2s^22p^4$ It has $4$ valence electrons which are shared with other atoms to form $4$ covalent bonds.

____________ is the crystalline allotrope of carbon.

chemistry the world of carbon organic compounds allotropes of carbon versatile nature of carbon

  1. Coal

  2. Coke

  3. Diamond

  4. Graphite

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Correct Option: C
Explanation:

Graphite is one of three forms of crystalline, or crystal-forming, carbon. Carbon also exists in an amorphous, or “shapeless,” form in substances such as coal and coke. Different forms of the same element are called allotropes. Besides graphite, the other allotropes of crystalline carbon are diamond and fullerenes


Hence, the correct options are $C$ and $D$

Which of the following elements shows allotropy ?

chemistry the world of carbon organic compounds allotropes of carbon versatile nature of carbon

  1. Mg

  2. Cs

  3. Sn

  4. Zn

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Correct Option: C
Explanation:

Allotropy is a phenomenon wherein an element especially from group $13$ to group $16$ exists in more than one form. These forms differ in arrangement of atoms in their crystalline form. Few list of various elements showing allotropy -

 

Forms | | --- | --- | | Carbon : | Graphite, Diamond, Fullerenes | | Sulphur $(S _{8})$: | Rhombic, Monocline, Triclinic sulphur | | Phosphorous $(P _{4})$:  | Red, Black, Yellow | | Tin $(Sn)$: | White, Grey |