Solution set of classtest based on Lesson

Number 13 Carbon: AnImportant Element

Q.1 Fill in the blanks.Answers (Write complete statements.)

a) layeredb)Peatc) fractional distillationd) ammonium cyanatee) fourf) carbon dioxide

Q.2 Answers

a) wrongCorrect sentence:-Fullerenes aresoluble in organic solvents.b) wrongCorrect sentence:-The purest formof coal is called anthracite.c) right

Q.3 Write odd one out.Ans.a) coke. Coke is an amorphousform of carbon while others arecrystalline forms of carbon.Ans.b) ethene.Ethene is anunsaturated hydrocarbon whileothers are saturated hydrocarbons.Ans.c) charcoal.Charcoal is not atype of coal while others aredifferent types of coal.

Q .4 Match thefollowing:-Answers.(i-c) ,(ii-d), (iii-a),(iv-b)

Q.5 Answer the following questions.Ans.a) The non crystalline form of carbon thatremains when coal gas is removed from coal iscalled coke.Ans.b) The hydrocarbons which have only singlebonds between carbon atoms are called saturatedhydrocarbons. Examples:-Ethane , Propane, Butaneetc.Ans.c) Elements occurring in more than one formwhere in the chemical properties of these differentforms are the same but their physical properties aredifferent is called allotropy. Example:-Carbon exist incrystalline forms like Diamond, Graphite, etc. and inamorphous forms like Coal , Coke, etc.

Ans.d) Covalent compounds are formed when twoor more atoms bond by sharing the valenceelectrons. Example:-MethaneProperties of covalent compounds:-I) Covalent compounds have low melting pointsand boiling points.II) Generally they are insoluble in water and solublein organic solvents.III) They are poor conductors of heat and electricity.Ans.e) The hydrocarbons having at least onemultiple bond (can be a double or a triple bond)between carbon atoms are called unsaturatedhydrocarbons. Examples:-Ethene, Propene,Propyne

Ans.f) Occurrence of carbon dioxide:-1) Carbon dioxide occurs in air in the freestate at the concentration of about 0.03%by volume.2) Exhaled air contains about 4% of carbondioxide.3) Carbon dioxide is the principal gasproduced by the combustion of wood, otherorganic materials, fossil fuel such as coal,petroleum, natural gas, etc.4) Carbon dioxide is present as a salt inchalk and shahabad tiles/marble/limestone.

Ans.g) In modern fireextinguishers, liquid and solidcarbon dioxide is filled underpressure. On reducing thepressure, it turns into gaseousstate and comes out forcefullythrough the horn -like horsepipe.

Q.6 Complete the crossword.

Q.7 Answers.(diagrams)

Thank you.By:- Mrs.Suchita Malpe