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CARBON AND ITS COMPOUNDS 

Important Questions
 

1. Explain sp2 hybridization with one example.
                         (or)
Explain the ability of C - atom to form two single covalent bonds and one double bond.      (AS 1) 4 Marks
A: Consider ethene/ethylene (CH2 = CH2) molecule as the example.

In the formation of CH2 = CH2 each carbon atom in its excited state undergoes sp2 hybridisation by intermixing one s - orbital (2s) and two p - orbitals (2px, 2py) and reshuffling to form three sp2 orbitals.
Now each carbon atom is left with one p orbital (pz) unhybridised.
The three sp2 orbitals having one electron each get separated around the nucleus of carbon atom at an angle of 120º.
When carbon is ready to form bonds one sp2 orbital of one carbon atom overlaps the sp2 orbital of the other carbon atom to form sp2 - sp2 sigma (σ) bond.
The remaining two sp2 orbitals of each carbon atom get overlapped by 's' orbitals of two hydrogen atoms containing unpaired electrons.
The unhybridised pz orbitals on the two carbon atoms overlap laterally as shown in figure to form a π bond.
Hence, there exists a sigma (σ) bond and a pi (π) bond between two carbon atoms in ethene molecule. Hence, the molecule ethene (C2H4) is

 

2. Explain sp3 hybridization with an example.
                                         (or)
Explain sp3 hybridisation in methane.     (AS 1) 4 Marks
A: The excited carbon atom allows its one s - orbital (2s) and three p - orbitals (2px, 2py, 2pz) to intermix and reshuffle into four identical orbitals known as sp3 orbitals.
The four electrons enter into the new four identical hybrid orbitals known as sp3 hybrid orbitals one each as per Hund's rule.

The hybridisation enables the carbon to have four identical sp3 hybrid orbitals and these have one electron each.
Since carbon has four unpaired electrons, it is capable of forming bonds with four other atoms may be carbon or atoms of some other monovalent element.
When carbon reacts with hydrogen, four hydrogen atoms allow their s orbitals containing one electron each to overlap four sp3 orbitals of carbon atom which are oriented at an angle of 109º28'.
Four orbitals of an atom in the outer shell orient along the four corners of a tetrahedron to have minimum repulsion between their electrons. The nucleus of the atom is at the centre of the tetrahedron.

overlap
This leads to form four sp3 - s sigma bonds between carbon atom and four hydrogen atoms. All these bonds are of equal energy.

 

3. Explain sp hybridization with an example.
                                      (or)
Explain the ability of carbon atom to form one single bond and one triple bond.      (AS 1) 4 Marks
A: Consider ethyne/acetylene (C2H2) molecule as the example.
In acetylene molecule there exists a triple bond between two carbon atoms and the fourth valency of each carbon atom is satisfied by hydrogen atoms (H - C   C - H)

In C2H5 molecule, there are two carbon atoms and two hydrogen atoms. In excited state each carbon atom undergoes sp - hybridisation by mixing its one s orbital and one p orbital and reshuffling to form two identical sp orbitals.
Each carbon atom has two unhybridised p - orbitals (2py, 2pz)

One sp - orbital of a carbon overlaps the sp orbital of other carbon to give sp - sp sigma bond.
The other sp orbital of each carbon atom overlaps the s orbital of a hydrogen atom to form a s - sp sigma bond.
The unhybridised p orbitals of one carbon atom laterally overlap the unhybridised p orbitals of other carbon atom to give two π bonds between two carbon atoms.
Thus ethyne molecule H - C   C - H and there exists three σ bonds and two π bonds in the molecule.

4. Explain the concept allotropy. Write about allotropes of the carbon. 
                                                                                                                                  (AS 1) 4 Marks
A: * 
The property of an element to exist in two or more physical forms having more or less similar chemical properties but different physical properties is called allotropy.
Allotropes form due to the difference in the arrangement of atoms in the molecule.
The allotropes of carbon are classified into two types. They are (a) Amorphous forms (b) Crystalline forms.

Different amorphous allotropes of carbon are coal, coke, wood, charcoal, animal charcoal, lamp black, gas carbon, petroleum coke, sugar charcoal etc.
Carbon in solid phase can exist in three crystalline allotropic forms
    a) Diamond         b) Graphite        c) Buckminster fullerene
The crystalline allotropes differ in their structures and they possess different physical properties.
Diamond and graphite form covalent network structures when as buckminster fullerene has a molecular solid with discrete C60 molecules.

 

5. Compare the structures of Diamond and Graphite.                     (AS 1) 4 Marks
A:
          
Diamond is a crystalline solid.

In diamond each carbon atom undergoes sp3 hybridisation in the excited state.
In diamond carbon atoms are in tetrahedral arrangement.
Each carbon atom is bonded to four other carbon atoms by covalent single bonds.
It is a giant molecule with cage like units in its structure. The structure is very hard to break and very compact.
The C - C bond length is 1.54 Aº and bond angle is 109º28'.

 

Graphite:
                
It is a grayish black soft crystalline solid with metallic lustre, and soapy to touch.

In graphite each carbon atom undergoes sp2 hybridisation in the excited state.
Graphite contains carbon atoms in hexagonal rings and the rings in turn are joined together to form a layer.
A series of such layers are piled one over the other to form graphite.
The C - C bond length in the hexagon is 1.42 Aº and the bond angle is 120º.
Two successive graphite layers are separated by 3.35 Aº.
The layers of carbon can slide one over the other because there are no strong covalent bonds between the atoms in the two adjacent layers.

 

6. Mention the unique properties of carbon.                                        (AS 1) 4 Marks
A: 
The unique properties carbon are catenation, isomerism, and formation of multiple bonds.
1) Catenation: Catenation is the phenomenon in which atoms of same element join together to form long chains. Carbon exhibits maximum catenation because of strong carbon - carbon bonds and tetravalence.
      Due to catenation, carbon atoms can form various types of straight chains, branched chains and ring structures, thus giving rise to a large number of compounds.

2) Isomerism: Compounds having same molecular formula but different structures are called isomers and the phenomenon is called isomerism. Carbon compounds exhibit isomerism i.e. for a particular molecular formula two or more compounds may exist. For example for the molecular formula C4H10, the following isomers are possible.
                  
                               N - Butane                                    Iso butane

3) Formation of multiple bonds: Carbon atoms are capable of forming multiple bonds with other carbon atoms. This further gives rise to a large variety of compounds.
         The following examples show carbon compounds with single, double and triple bonds.
         CH3 - CH2 - CH3          CH3 – CH = CH2              CH3 –C -= CH
           n - Propane                 Propene                          Propyne

 

7. Define Homologous series. Mention the characteristic properties of them.
                                                                                                                                  (AS 1) 4 Marks
A: 
The series of carbon compounds in which two successive compounds differ by - CH2 unit is called homologous series.
e.g.: CH4, C2H6, C3H8, C4H10, .....

 

Characteristic features of homologous series are:
* They have one general formula
e.g.: Alkanes (Cn H2n + 2)
         Alkynes (Cn H2n - 2)
* Successive compounds in the series possess a difference of (-CH2) unit.
* They possess similar chemical properties due to the same functional group.
e.g.: Alcohols, aldehydes and carboxylic acids have functional groups C - OH, C - CHO and C - COOH respectively.
*  They show a regular gradation in their physical properties.

 

8. Complete the table given with the hydrocarbons- C2H2, CH4, C2H4, C2H6, C3H8, C3H6, C3H4, C4H6, C4H8, C4H10, C5H10, C5H12, C5H8 and answer the questions given below.  (AS 4) 4 Marks

Alkanes

Alkenes

Alkynes

 

 

 

i) Which among the above are saturated hydrocarbons?

ii) Write the general formula of Alkenes.
iii) What is the formula of butane?
iv) Draw the structure of Ethene (C2H4).
A:

Alkanes

Alkenes

Alkynes

CH4

C2H4

C2H2

C2H6

C3H6

C3H4

C3H8

C4H8

C4H6

C4H10

C5H10

C5H8

C5H12

 

 

i) Alkanes are saturated hydrocarbons.
ii) General formula of Alkenes is CnH2n
iii) Butane formula C4H10

 

9. Complete the following table.      (AS 4) Marks

Functional group

Formula

Prefix

Suffix

Acid Halides

- COX

Halo

carbonyl

Alcohol

 

 

 

 

- NH2

 

Amine

Ether

R - O - R

 

-

Esters

- COOR

 

(R).. Carboxylate

Aldehydes

 

Formyl

Carboldehyde

Carboxylic acid

-COOH

 

Carboxylic acid

 

- CN

 

Carbonytrile

A:

Functional group

Formula

Prefix

Suffix

Acid Halides

- COX

Halo carbonyl

Carbonyl halide

Alcohol

- OH

hydroxy

ol

Amines

- NH2

amino

Amine

Ether

R - O - R

(R) oxy

     -

Esters

- COOR

oxycarbonyl

(R).. carboxylate

Aldehydes

- CHO

Formyl

Carboldehyde

Carboxylic acid

-COOH

Carboxy

Carboxylic acid

Nitriles

- CN

cyano

- carbonytrile

 

 

10. Write the principle of Nomenclature of a carbon compound.           (AS 1) 4 Marks
A: Principles of Nomenclature:

Numbering carbon atoms:

* We can number the carbon atoms from left to right or from right to left. So that sum of the numbers indicating the positions of substituents and functional groups should be minimum possible.
The functional group carbon should be given the lowest number even if it does not obey rule (1).
The carbon atoms of the chain terminating. Functional group say -CHO, or -COOH groups should be given always number '1' even if it does not obey Rules (1) & (2).

 

Longest chain rule: Select the longest continuous chain of carbon atom which is known as parent chain or principle chain. All the other carbon atoms constitute in the chain are branched chains or side chains.
                       

Lowest number rule: The carbon compound which contains only one substituent number the carbon atom in such a way that the carbon atom carrying the substituent get the lowest number.
   
Lowest sum rule: If there are two or more substituents in the carbon compounds the parent chain is numbered from the end which gives the lowest sum of more substituent carbon.
        
Alphabetical order: When two or more different groups are present, such groups are arranged in alphabetical order.

 

11. Write the IUPAC names of the following compounds.    (AS 1) 4 Marks
      


A: 
i) 2, 3 - di bromo; 2, 3 - di chloro pentane
      ii) Cyclo pentane
      iii) 1, 2 - di chloro cyclo butane
      iv) 2, 3 - di methyl - cyclo - hexan - 1 - ol

 

12. Write the structural formulae for the following compounds.  (AS 1) 4 Marks
i) 7 - hydroxy heptane - 2 - one
ii) 2, 3 - di chloro propanal
iii) 2 - methyl pentan - 3 - ol
iv) 5, 6 - di chloro - octa - 6, 7 - di en - 1, 2 - di ol

 

 

13. How many isomers can be drawn for pentane with molecular formula C5H12? What are they? Draw their structures and mention their common names.   (AS 1) 4 Marks
A: 
Isomers of pentane are three. These are
i) n - pentane
ii) Iso pentane
iii) Neo pentane

 

Structures:
i) n - pentane: CH3 - CH2 - CH2 - CH2 - CH3

 

14. Write the molecular formula of the first four compounds of the homologous series of aldehydes.    (AS 1) 4 Marks
A:
 Homologous series of aldehydes are formaldehyde, acetaldehyde, propionaldehyde and butanaldehyde.

 

15. Draw the structures of isomers of butane.       (AS 1) 4 marks
A: 
Isomers of butane are n - butane, Iso butane

 

Structures:

 

16. Explain some important reactions with examples that takes place in carbon compounds.       (AS 1) 4 Marks
A: Important reactions in organic compounds are

i) Combustion reaction
ii) Oxidation reactions
iii) Addition reactions
iv) Substitution reactions

 

i) Combustion reaction: The process of burning of carbon or carbon compounds in excess of oxygen or air to give carbon dioxide, heat and light is called combustion reaction.
e.g.: CH4 + 2 O2  CO2 + 2 H2O + Energy

ii) Oxidation reactions: Combustion is generally oxidation reaction. Oxidation reactions may be carried out using oxidizing agents.
e.g.: Ethyl alcohol undergoes oxidation with alkaline KMnO4 solution to form acetaldehyde and finally acetic acid.  

 

iii) Addition reactions: Unsaturated organic compounds contains either double or triple bonds. Unsaturated organic compounds under go addition reactions to form saturated compounds.

 

iv) Substitution reactions: A reaction in which an atom or a group of atoms in a given compound is replaced by other atom or group of atoms is called a substitution reaction.
e.g.: Methane reacts with chlorine in the presence of sunlight to form a mixture of methyle chloride, Methylene chloride, chloroform and carbon tetra chloride.
CH4 + Cl2           CH3Cl                       +       HCl
Methane                           Methyle chloride

CH3C+ Cl2         CH2Cl2                    +       HCl
                                             Methylene chloride
CH2Cl2 + Cl     CHCl3                        +      HCl
                                                Chloroform
CHCl3 + Cl2        CCl4                           +       HCl
                                                Carbon tetrachloride

 

17. All combustion reactions are oxidation reactions, but all oxidation reactions are not combustion reactions. Explain with an example.      (AS 1) 4 Marks
A: 
Carbon and its compounds burn in presence of oxygen or air to give CO2, heat and light the process of burning of carbon (or) carbon compound in excess of oxygen to give heat and light is called the combustion reaction.
e.g.: 1) C + O2  CO2 + Energy
          2) 2 C2H6 + 7 O2  4 CO2 + 6 H2O + Energy

* Though combustion is generally oxidation reaction, all oxidation reactions are not combustion reactions. Oxidation reactions may be carried out using oxidaizing agents. Oxidizing agents or oxidants are substances that oxidize other substances. They themselves undergo reduction.
 

e.g.: Alkaline potassium permanganate (or) acidified potassium dichromate in solutions acts as oxidizing agents and supplies oxygen to convert alcohols into carboxylic acids. Ethyl alcohol undergoes oxidation to form the product acetaldehyde and finally acetic acid.

* From these reactions addition of oxygen is called oxidation where as burning of a substance in air called combustion. However these two reactions absorb heat and oxygen is added to them.
* Hence every combustion reaction is an oxidation but not all the oxidation reactions are combustion.

 

 

18. Explain the substitution reaction of methane with chlorine.        (AS 1) 4 Marks
A: 
Methane reacts with chlorine in the presence of sunlight or on heating. These reactions are called substitution reactions because in these reactions hydrogen atoms of methane are replaced by halogen atoms.
CH4 + Cl2              CH3Cl                  +                HCl
Methane                             (Methyle chloride)            Hydrogen chloride
                                                      (or)
                                              Chloro methane
       In this reaction -H atom of methane has been replaced by a Cl- atom converting CH4 to CH3Cl. However, if Cl2 is used in excess, all the hydrogen atoms are replaced by chlorine atoms one by one.
CH3C+ Cl2     
       CH2Cl2                        +                 HCl
Methyl chloride                     Di-Chloro methane             Hydrogen chloride
                                                 (or) Methylene chloride

CH2Cl2 + Cl2            CHCl3                         +                  HCl
Dichloro Methane                    Trichloro Methane            Hydrogen chloride
                                                     (or) Chloroform
CHCl3 + Cl2              CCl4                             +                 HCl
Trichloro Methane                 Tetrachloro Methane           Hydrogen chloride
                                                 (or) Carbon Tetra chloride

 

19. What do you understand about functional group. Explain
                                               (or)
Mention the functional groups in carbon compounds.     (AS 1) 4 Marks
A: 
The characteristic properties of an organic compound depend mainly on an atom or group of atoms in its molecule known as the functional group.
        Functional groups are responsible for the behaviour of the organic compounds. Compounds containing the same functional group undergo similar types of reactions. Each functional group has its own characteristic properties irrespective of other part of the molecule.

 

Name of functional group

Formula of functional group

Example

Alcohol

- C - OH

CH3OH

Aldehyde

- C - CHO

CH3CHO

Ketone

CH3 - COCH3

Acid

C - COOH

CH3COOH

Ether

- C - O - C

CH3 - O - CH3

Amine

- C - NH2

CH3 - NH2

Ester

- C - COOR

CH3COOCH3

 

20. Explain the cleansing action of soap.
                                 (or)
Instead of using just plain water to clean clothes, why do we use detergent? How does it remove dirt from clothes? Explain.     (AS 1) 4 Marks
A: 

The dirt of dirty cloth, which is put in a soap solution, is mainly greasy matter.
The soap molecules are arranged radially with hydrocarbons ends directed inwards into the greasy matter and ionic part directed outwards into water.

When a dirty cloth is inserted in the solution then the hydrocarbon part sticks to the dirt or oil. With a little agitation, the dirt particles get entrapped by the soap micelles and get dispersed in water due to which the soap water gets dirty and the cloth gets cleaned.
Soaps and detergents make oil and dirt present in a cloth dissolve in water, there by making the cloth clean.
Soap has one polar end (the end with -  -O Carboxy) and one non - polar end (the end with hydrocarbon chain) as shown in the figure given below.
                     
The polar end is hydrophilic in nature i.e., this end is attracted towards water, while the non-polar end is hydrophobic in nature i.e, it is attracted towards water.
When soap is dissolved in water its hydrophobic ends attach themselves to dirt and remove it from the cloth.

The hydrophobic end of the soap molecules move towards the dirt or grease particle. The hydrophobic ends are attached to the dirt particle and try to pull out.
The molecule of soap surround the dirt particle at the centre of the cluster and form a spherical structure called micelle.
These micelles remain suspended in water like particles in a colloidal solution
The various micelles present in water do not come together to form a precipitate as each micelle repels the other because of the ion-ion repulsion.
Thus, the dust particles remain trapped in micelles (Which remain suspended) and are easily rinsed away with water. Hence, soap micelles remove dirt by dissolving it in water.

 

21. How do you test the cleansing action of soap?     (AS 3) 4 Marks
A: * 
Take about 10 mof water in two test tubes.
Add a drop of cooking oil to both the test tubes and lable them as A and B.
Add a few drops of soap solution to test tube B.
Now shake both the test tubes vigorously for the same period of time.

We cannot observe that the oil and water layers separately in both the test tubes immediately after shaking is stopped.
Leave the test tubes undisturbed for some time and observe.
we observe the separation of oil layer in test tube B, because it contains the soap solution.
This gives an idea of cleansing action of soap.

 

22. Draw the diagram showing up sp hybridisation in Ethyne.   (AS 5) 2 marks
A:
            

 

23. Explain the esterification reaction.            (AS 1) 2 Marks
A: * 
The reaction between carboxylic acid and an alcohol in the presence of conc. H2SO4 to form sweet odoured substance, ester is called esterification.


* Acetic acid reacts with ethyl alcohol in presence of Con.H2SO4 to form ethyle acetate.

 

24. Explain the saponification reaction.     (AS 1) 2 Marks
A: 
When fats are treated with sodium hydroxide, sodium salts of fatty acid (soap) and glycerol is formed. This reaction is called saponification reaction.
   

 

25. Draw the figure of methane molecule showing its hybrid orbitals. (AS 5) 2 Marks

 

26. Name the following functional groups.       (AS 1) 2 Marks
     i) - CHO         ii)    C = O         iii) - OH           iv) - COOH
A: i) Aldehydes
     ii) Ketones
     iii) alcohols
     iv) Acids

 

27. Identify the functional groups in the following compound and write IUPAC names.       (AS 1 ) 2 Marks
                           Cl                                  CH3  O 
                           |                                     |        ||
i) CH3 - CH2 - CH - CHO    ii) CH3 - CH - C - CH3
                                                                         Cl
                                                                          
|
A: The functional group present in CH3 - CH2 - CH - CHO is aldehyde
The IUPAC name of the compound is 2 - chloro - Butan - 1 - ol

                                                                      CH3   O
                                                                         |        ||
ii) The functional group present in CH3 - CH - C - CH3 is ketone.
The IUPAC name of the compound is 3 - Methyle - 2 - Butan - one

 

28. Complete the following reactions.       (AS 1) 2 Marks
i) CH3COOH + NaOH 

ii) CH3 - CH = CH - CH3 + H2 
A: i) CH3COOH + NaOH  CH3COONa + H2O
     ii) CH3 - CH = CH - CH3 + H2  CH3 - CH2 - CH2 - CH3

 

29. Write the general formula of alkanes and give some examples. (AS 1) 2 Marks
A: 
The general formula of alkanes is CnH2n + 2
e.g.: Methane (CH4)
          Ethane (C2H4)
          Propane (C3H8)
          Butane (C4H10)

 

30. Write the general formula of Alkenes and give some examples.     (AS 1) 2 Marks
A: 
The general formula of Alkenes is Cn H2n
e.g.: Ethene (C2H4)
          Propene (C3H6)
          Butene (C4H8)

 

31. Write the general formula of alkynes and give some examples.    (AS 1) 2 Marks
A: 
The general formula of alkynes is Cn H2n - 2
e.g.: Ethyne (C2H2)
          Propyne (C3H4)
          Butyne (C4H6)

 

32. Write the general formula of halo hydrocarbons and give some examples.     (AS 1) 2 Marks
A: 
The general formula of halogen derivatives or halo hydrocarbons is
     Cn H2n + 1 X or R - X
e.g.: Methyle Chloride (CH3Cl)
          Ethyl Chloride (CH3CH2Cl)

 

33. Write the general formula of carboxylic acids and give some examples.     (AS 1) 2 Marks
A: 
The general formula of carboxylic acids is R - COOH
e.g.: Formic Acid (H - COOH)
         Acetic acid (CH3 - COOH)

 

34. Write the general formula of primary amines and give some examples.      (AS 1) 2 Marks
A: 
The general formula of primary amines is R - NH2
e.g.: Methyl amine CH3 - NH2
          Ethyl amine CH3CH2 - NH2

 

35. Write the structural formulae for the following compounds.
       i) 3 - chloro - 2 - methyle pentane
       ii) 1, 3 - hexa dien - 5 - yne      (AS 1) 2 Marks

                     CH3
                      |
A: i) CH3 - CH - CH - CH2 - CH3 
                               |                                
                              Cl
     ii) CH -= C - CH = CH - CH = CH2

 

36. Write the IUPAC names of the following compounds.
                 CH3
                  
|
i) CH3 - C - CH2 - CH2 - CH = CH2
                       

               CH3
ii) CH2 = CH - CH - CH2 Cl                 (AS 1) 2 Marks 

                              |
                             Cl
A: i) 5, 5 - di methyle - 1 - hexene
     ii) 3, 4 - di chloro - 1 - butene

 

37. How are hydrocarbons classified? Explain.       (AS 1) 2 Marks (or) 4 Marks
A: * 
The compounds containing only carbon and hydrogen in their molecules are called hydrocarbons.
Hydrocarbons are classified into two categories known as open chain hydrocarbons and closed chain hydrocarbons. Open chain hydrocarbons are also called aliphatic hydrocarbons or acyclic hydrocarbons.

e.g.: CH3 - CH2 - CH2 - CH2 - CH3 (open chain hydrocarbons) 

All hydrocarbons (both aliphatic and cyclic hydrocarbons) are again classified as alkanes, alkenes and alkynes.
Hydrocarbons containing only single bonds between carbon atoms are called alkanes. (C - C)
Hydrocarbons containing atleast one double bond between carbon atoms are called alkenes. (C = C)
Hydrocarbons containing atleast one triple bond between carbon atoms are called alkynes. (C = C)

 

38. Discuss about saturated and unsaturated hydro carbons     (AS 1) 2 Marks
A: * 
Hydrocarbons containing only C - C single bonds are known as saturated hydrocarbons
e.g.: Alkanes.
Hydrocarbons that contain atleast one double bond or one triple bond between the two carbon atoms are called unsaturated hydrocarbons.
e.g.: Alkenes, Alkynes etc.

 

39. Mention the crystalline and non-crystalline allotropic form of carbon.   (AS 1) 2 Marks
A: * 
The allotropes of carbon are classified into two types they are (a) amorphous forms (b) crystalline forms.
Different amorphous allotropes of carbon are coal, coke, wood, charcoal, animal charcoal, lamp black, gas carbon, petroleum coke, sugar charcoal etc.
Carbon in solid phase can exist in three crystalline allotropic forms
a) Diamond
b) Graphite
c) Buckminster fullerene

 

40. What is meant by soap? Write the formula of soap.  (AS 1) 2 Marks
A: * 
Soap is a sodium or potassium salt of a higher fatty acid like palmitic acid, stearic acid, oleic acid etc.
The general formula of a soap is R - COONa or R - COOK where
R = C15H31, C17H35 etc.

 

41. Draw a diagram of soap particle.   (AS 5) 1 Mark
A:

 

42. Draw a diagram of micelle.   (AS 5) 1 Mark
A:
        

 

43. Write the uses of fullerenes.     (AS 6) 1 Mark
A: 
Fullerenes are under study for potential medicinal use such as specific antibiotics to target resistant bacteria and even target certain cancer cells such as melanoma.

 

44. Write the uses of nanotubes.    (AS 6) 2 Marks
A: * Nanotubes are electrical conductors and can be used as molecular wires.

In integrated circuits nanotubes are used instead of copper to connect the components together.
Scientists inserted biomolecules into nanotubes to inject them into a single cell.

 

45. Write an use of vinegar.   (AS 6) 1 Mark
A: 
Vinegar is used widely as a preservative in pickels.

 

46. How do you understand the writings of a pencil on a paper.   (AS 6) 1 Mark
A: 
When we write with a pencil, the inter layer attractions breakdown and leave graphite layers on the paper.

 

47. Write the uses of Graphite.       (AS 6) 1 Mark

A: Graphite is used as lubricant and as the lead in pencils.

 

48. Write the uses of Diamond.       (AS 6) 1 Mark
A: 
i) Diamond is used as precious stone for jewellry.
     ii) Diamond is used as abrasive for cutting glass, drilling rocks etc.

 

49. Which is a good motor fuel.      (AS 6) 1 Mark
A: 
Solution of about 10% Ethanol in gasoline is a good motor fuel.

 

50. Write the uses of ethyl alcohol.    (AS 6) 1 Mark
A: 
Ethyl alcohol is used in medicines such as tincture of Iodine, cough syrups and many tonics.

 

51. Why do sometimes cooking vessels get blackened on a gas or kerosene stove?    (AS 6) 1 Mark
A: 
Because of the inlets of air getting closed. The fuel gases do not completely undergo combustion. Hence, it forms a sooty carbon form which gets coated over the vessels.

 

52. Which hydrocarbons burn with bright blue flame and used as fuels?        (AS 6 ) 1 Mark
A: 
Saturated hydrocarbons.

 

53. Which is called grain alcohol?     (AS 6) 1 Mark
A: 
Grains such as corn, wheat, barley are common sources for ethanol, it is also called grain alcohol.

 

54. Name the acid present in vinegar.      (AS 1) 1 Mark
A: 
Acetic acid

 

55. Which hydrocarbons participate in addition reactions?  (AS 1) 1 Mark
A: 
Unsaturated hydrocarbons (Alkenes, Alkynes).

 

56. What do we call the compounds formed by C, H, X?      (AS 1) 1 Mark
A: 
Halo hydrocarbons.

 

57. Name the following compound           (AS 1) 1 Mark
                
A: 
5 - chloro 4, 6 - dimethyl cyclo hexa - 1, 3 diene - 1 - ol

 

58. Explain the reaction of Ethanol with Na.     (AS 1) 1 Mark
A: 
Ethanol reacts with metallic sodium to liberate hydrogen and form sodium ethoxide.
   2 C2H5OH  +  2 Na       2 C2H5ONa + H2
        Ethanol                                 Sodium ethaxide

 

59. Which substance is used to detect the ethanol in the drivers breath?   (AS 6) 1 Mark
A: 
K2Cr2O7

 

60. The IUPAC name of the compound CH3 - CH2 - C = CH2 is?   (AS 1) 1 Mark

                                                                                                         | 
                                                                                                        CH3
A: 2 - Methyl 1 - butene.

 

Short Answer type Questions

1. Which type of Hybridization involved in CH4? (AS1) 1 Mark
A: sp3

 

2. What is the shape and bond angle of CH4 molecule? (AS1) 1 Mark
A: Tetrahedral and bond angle is 109°.28'

 

3. What are the Hybridizations involved in Ethene and Ethyne? (AS1) 1 Mark
A: Ethene - sp2, Ethyne - sp

 

4. How many σ and π bonds are present in between carbon atoms of Ethyne molecule?  (AS1) 1 Mark
A: Two π bonds and one σ bond.

 

5. Among the following which one has less bond distance between the carbon atoms?
      1) C2H6           2) C2H4              3) C2H2                                                                                  (AS1) 1Mark
A: C2H2 has less bond distance due to multiple bonds.

 

6. What type of Hybridization present in buckminsterfullerene? (60C) (AS1) 1 Mark
A: sp2

 

7. In buckminsterfullerene, how many pentagonal and hexagonal faces exists? (AS1) 1 Mark
A: Pentagonal faces - 12 and Hexagonal faces - 20.

 

8. Draw the structure of urea molecule. (AS5) 1 Mark
A:
               

 

9. Which substance is formed on heating Ammonium cynate. (AS1) 1 Mark
A: Urea

 

10. Which type of Hydrocarbons are called saturated Hydrocarbons?  (AS1) 1 Mark
A: (Alkane) Hydrocarbons having single bonds are called saturated Hydrocarbons.

 

11. Write general formula for Alkynes. (AS1) 1 Mark
A: CnH2n - 2

 

12. Write functional Isomers for alcohol. (AS1) 1 Mark
A: Ethers.
    e.g.: CH3 - CH2 -OH                         CH3 - O - CH3
                   Alcohol                                        Ethers

 

13. Which of the following molecule is called buckminsterfullerene?
      C30, C60, C70, C90 (AS1) 1 Mark
A: C60

 

14. What is the general name of all the compounds made up of carbon and hydrogen?    (AS1) 1 Mark

A: Hydrocarbons
 

15. How many Isomers of the following Hydrocarbons are possible?
      (i) C4H10        (ii) C5H12    (AS1) 1 Mark
A: (i) Two    (ii) Three

 

16. Which allotropic form of carbon has layered structure? (AS1) 1 Mark
A: Graphite

 

17. What is the distance between any two adjacent layers in graphite? (AS1) 1 Mark
A: 3.35 A°

 

18. Nano tubes are discovered by which scientist? (AS1) 1 Mark
A: Sumio li jima

 

19. Name the element whose one of the allotropic forms is buckminsterfullerene.  (AS1) 1 Mark
A: Carbon

 

20. Name the hardest natural substance known. (AS1) 1 Mark
A: Diamond

 

21. Name the element whose allotropic form is graphite. (AS1) 1 Mark
A: Carbon

 

22. Give the general formula of an
        i) alkane                 ii) alkene           iii) alkyne  (AS1) 2 Marks
A: i) alkane: CnH2n + 2
     ii) alkene: CnH2n
     iii) alkyne: CnH2n - 2

 

23. Classify the following compounds as alkanes, alkenes and alkynes.
       C2H2, C2H4, C2H6, C3H6, C3H4, C3H8 (AS1) 2 Marks
A: alkanes: C2H6, C3H8
     alkenes: C2H4, C3H6
     alkynes: C2H2, C3H4

 

24. Which of the following compounds can have a triple bond?
       C3H6, C3H8, C3H(AS1) 1 Mark
A: C3H4

 

25. Which of the following compounds can have a double bond?
       C2H6, C3H4, C5H10 (AS1) 1 Mark
A: C5H10

 

26. Which of the following hydrocarbons is unsaturated?
     C5H12, C3H8, C4H8 (AS1) 1 Mark
A: C4H8

 

27. Complete the following equations.
       i) 2 C2H5OH + 2 Na  
      ii) 2 CH3COOH + 2 Na            (AS1) 2 Marks
A: i) 2 C2H5OH + 2 Na   2  C2H5ONa + H2
     ii) 2 CH3COOH + 2 Na  2  CH3COONa + H2

 

28. Complete the following equations.

 

29. Complete and balance the following equations.

 

30. Write the structure of 5, 6 - dichloro - oct - 6, 7 - di en - 1, 2 - di ol. (AS1) 1 Mark
A: 
       

 

 

31. Write the structure of 3 - Bromo - 1 - cyclo pentene. (AS1) 1 Mark
A:
        

 

32. Write the structure of 3 - bromo - 2 - chloro - 5 - oxo - hexanoic acid.
                                                                                                                            (AS1) 1 Mark
A:
       

 

33. Write the IUPAC names of the following compounds.


A: i) 2, 4, 6, 6 tetra methyl hept - 2 - ene
     ii) 5 - bromo - 2 - methyl - hex - 1 - ene - 3 - yne

 

 

34. Write the IUPAC names of the following compounds.
     
A: i) 5 - Chloro - hex - 3 - yne -1 - al
     ii) 2, 3 - dimethyl but - 2 - ene

Posted Date : 16-11-2020

గమనిక : ప్రతిభ.ఈనాడు.నెట్‌లో కనిపించే వ్యాపార ప్రకటనలు వివిధ దేశాల్లోని వ్యాపారులు, సంస్థల నుంచి వస్తాయి. మరి కొన్ని ప్రకటనలు పాఠకుల అభిరుచి మేరకు కృత్రిమ మేధస్సు సాంకేతికత సాయంతో ప్రదర్శితమవుతుంటాయి. ఆ ప్రకటనల్లోని ఉత్పత్తులను లేదా సేవలను పాఠకులు స్వయంగా విచారించుకొని, జాగ్రత్తగా పరిశీలించి కొనుక్కోవాలి లేదా వినియోగించుకోవాలి. వాటి నాణ్యత లేదా లోపాలతో ఈనాడు యాజమాన్యానికి ఎలాంటి సంబంధం లేదు. ఈ విషయంలో ఉత్తర ప్రత్యుత్తరాలకు, ఈ-మెయిల్స్ కి, ఇంకా ఇతర రూపాల్లో సమాచార మార్పిడికి తావు లేదు. ఫిర్యాదులు స్వీకరించడం కుదరదు. పాఠకులు గమనించి, సహకరించాలని మనవి.

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