Carbon and its Compounds Class 10

 Carbon and its Compounds

1) Name the simplest hydrocarbon?

A)The simplest hydrocarbon is methane (CH4).

2) what are the general molecular formulae of alkanes, alkenes and alkynes? 

Ans) 

Si. No. Hydrocarbon   general molecular formula

1.  Alkanes.    Cn H 2n+2

2.  Alkenes.       Cn H 2n

3.  Alkyenes.    Cn H 2n-2

Where n=number of carbon atoms

3] Give the IUPAC name of the following compounds. If more than one compound is possible, name all of them.

    1. An aldehyde derived from ethane.

    2. Hay ketone derived from butane.

    3. A chloride derived from propane.

    4. An alcohol derived from pentane.

Ans:-

  1. An aldehyde derived from ethane is "Ethanal" (CH3CHO) (or) CH3 - C = 0

                                                       |

                                                      H

  2. Ketone derived from butane is Butanone (or) Butane -2- one

        

               C4H10 = CH3 COC2H5                                   Butane     Butanone

 3. Chloride derived from propane is

 a) Propyl Chloride.    b) 2- Chloro- Propane

   (Chloro propane).      CH3---CH---CH3

 CH3-CH2-CH2CL                      |

                                                   CL

4. Alcohol travel from pentane

                                        H  H  H  H  H  

a) 1- Pentanol.               |    |    |    |    |

                                 H --H--C--C--C--C-- OH

                                         |   |    |    |    |

                                        H  H  H  H  H

b) Pentane-3-ol.                              OH

                                                             |

                             H3C--CH2--CH2--CH--CH3

c) Pentane-3-ol.                    OH

                                                  |

                            CH3--CH2--CH--CH2--CH3

4. Name the simplest Ketone and write its molecular formula.

A) The simplest kept on is kept on formula CH 3 - C O - CH3.

5. Name the compound formed by heating ethanol and 443 k with excess of concentrated H2So4 .

 Ans:ethanol when heated with excess of corn . H2So4 at 443 k produces ethene 

CH3CH2OH gives rise to Con. H2SO4/ 443k -----> C2H4 + H2O.

6. Explain the cleaning action of soap?

Cleaning action of soap: we put dirty cloth in the solution . Dirt is mainly greasy matter.The soap molecules arranged radically with hydrocarbonate ends directed inwards into greasy matter and ionic part directed outwards into water

When a dirty cloth is inserted in the sol 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 cloth gets cleaned

7)Explain the structure of graphite in  terms of bonding and give one property based on this structure.

A) Graphite forms a two dimenstional layer structure with C-C bonds within the layers.There is                   relatively weak interaction between the layers.In the layer structure,the carbon atoms are in a trigonal planar environment.This is consistent with each carbon atom in sp² hybridization.Interactions between the sp² orbitals (overlaps) lead to the formation of C-C bonds. Each carbon atom is with one unhybridized 'p' orbital. The unhybridized 'p' orbitals interact to form a π system that is delocalised over the  whole layer. The interactions know as London dispersion forces between the layers which are separated by a distance of 3.35 A degree are weakened by the presence of water molecules so that it is easy to cleave graphite. For this reason graphite is used as lubricant and as 'lead' in pencils

8) Name the acid present in vinegar? 

A) The acid present in vinegar is 5-8% Ethanoic acid. Its formula is CH3CooH.

9) What happens when a small piece of sodium is dropped in to ethanol?

A).when a  small piece of sodium is dropped into ethanol it releases Hydrogen gas.

                    2C2H5OH     +        2Na        →        2C2H5ONa        +      H2↑

10)A mixture of oxygen and ethyne is burnt for welding, can you tell why a mixture of ethyne and air is not used?

A)1.The heat and temperature produced by an acetylene flame depend upon the amount of oxygen used to burn it.

    2. Air - acetylene produces a flame temperature of around 4000°F. This is hot enough to solder                  aluminum work glass, repair radiators and braze plumbing fixtures.It is not hot enough to weld  steel.

    3.When acetylene is burned in pure oxygen, the flame temperature may be as high as                          5730°C.However, the flame temperature and the amount of heat generated depend upon the ratio of oxygen to acetylene used.