C3.3 Organic Chemistry I – LearnITbyTests

1. What are the physical properties of alkenes?

It’s melting and boiling point increases as the carbon number per molecule increases and also due to the increase in the van der Waals’ forces of attraction

Its density increases as the carbon number per molecule increases

Ethene, propene and butenes are gases at room temperature and the rest are liquid state

All of the above

2. What is the name of the process in which covalent bonds of halogens are broken in the presence of light and one of the atoms comprising the covalent bond gets all the two electrons whereas the other gets none? E.g. X ÷ Y = X+ + Y

Homolytically

Heterolytically

Both A and B

None of the mentioned

3. Mention the chemical properties of alkenes

Alkenes react with oxygen and they are oxidized to carbon [IV] oxide and water with release of heat

Involved in addition reactions with halogens, bromine water, hydrogen bromide, concentrated sulphuric acid etc

Polymerization reactions where alkene molecules join together to form very large molecules (polymers)

All of the above

4. Discuss the chemical reaction of alkanes

Alkane’s burn in oxygen to form carbon dioxide and water accompanied by the release of a lot of energy

Alkanes react with halogens only in the presence of light.

Both B and A

None of the above

5. Which of the following STATEMENT IS CORRECT about alkanes

Are saturated hydrocarbon

They have single bond throughout with a functional group C-C

Alkanes are represented by the general formula CnH2n + 2

All of the above

6. Which of the following statement s correct about the alkenes?

Are unsaturated hydrocarbon

They have a double bond with a functional group as C=C

They have a general formula of CnH2n

All of the above

7. Mention the hydrocarbon whose functional group is C-C

8. What is the chemical laboratory indication of methane gas during an experiment

On bringing a burning splint of wood it burns with a pop sound

On bringing a burning splint of wood it puts out the flame.

On bringing a burning splint of wood it burns with a non-sooty flame

None of the above

9. Discuss the uses of alkenes

Ethene is used to manufacture plastics i.e. poly [ethene] and polychloroethene [PVC].

Ethene is also used in the manufacture of ethanol and ethanol

Propene is used to manufacture propanone which is used as a solvent and a raw material for the manufacture of plastics.

All of the above

10. Mention the hydrocarbon whose functional group is C=C

11. Mention the 3 homologous series

Saturated alkanes

Unsaturated alkynes

Unsaturated alkenes

All of the above

12. The first two members of the alkyne homologous series contain no isomers. True or false

TRUE

FALSE

Maybe

None of the above

13. Mention the chemical properties of alkynes

Oxidation reactions i.e. alkynes are oxidized by oxygen to carbon [IV] oxide and water

Additional reaction i.e. alkynes undergo an addition reaction with halogens, hydrogen and hydrogen halides

Both A and B

None of the above

14. Hydrocarbon molecule which has a single carbon bond is said to be

Saturated hydrocarbon

Unsaturated hydrocarbon

Both A and B

None of the above

15. Hydrocarbon molecule which has double or triple or more carbon bonds are said to be

Saturated hydrocarbon.

Unsaturated hydrocarbon

Both A and B

None of the above

16. Mention the hydrocarbon whose functional group is C=C

17. What are the physical properties of alkanes?

Melting and boiling points increase as the carbon atoms per molecule increases

Density increases as the carbon atoms per molecule increases.

Only methane, ethane, propane and butane exists in gaseous form the rest exist in liquid form

All of the above

18. Ethyne gas is prepared in the laboratory when 1, 2 – dibromoethane is run drop wise into a boiling solution of ethanolic potassium hydroxide. True or False

FALSE

maybe

TRUE

None of the above

19. Hydrocarbons are organic compounds that contain carbon and hydrogen only in their molecules

TRUE

FALSE

Maybe

None

20. What is the chemical lab confirmation of ethane gas during an experiment?

On bringing a burning splint of wood it burns with a pop sound

On bringing a burning splint of wood it puts out the flame

On bringing a burning splint of wood it burns with a sooty flame.

None of the above

21. Ethene gas is prepared in the laboratory by heating a mixture of ethanol and concentrated sulphuric acid at high temperatures. True or False

TRUE

FALSE

Maybe

None of the above

22. Mention 3 uses of butane

Manufacture of buta- 1, 3 – diene for use as an additive in synthetic rubber during vulcanization

Used in the manufacture of 2-methyl propane which is used in the manufacture of 2, 2, 4- trimethylpentane which is high-grade petrol.

As a fuel e.g. cooking gas and laboratory gas for heating.

All of the above

23. What is the name of the process in which covalent bonds of halogens are broken in the presence of light and each of the atoms composing the covalent bond is left with an electron? E.g. X ÷ Y = X° + Y°

Homolytically

Heterolytically

Both A and B

None of the mentioned

24. A family of compounds having the same functional groups is referred to as

25. Which statement is CORRECT about a functional group of a hydrocarbon molecule

Is an identifying feature that is found within a group of organic compound e.g. C=C

Are the ones involved in a chemical reaction

Responsible for the characteristics of an organic compound

All of the above

26. Which of the following statement is CORRECT about alkynes?

There are unsaturated hydrocarbons

They have a general formula of CnH2n-2

they contain C-C triple bond (C=C) AS THE FUNCTIONAL GROUP

All of the above

27. Discuss how alkenes are named [Nomenclature of alkenes]

The parent chain must contain the double bond C=C.

The lowest of the possible numbers of the carbon atoms to which the double bond is attached is used in the name of the alkene

The alkenes are all named with the suffix –ENE and the position of the double bond are indicated

All of the above

28. Mention the 2 ways on how covalent bonds of halogens can be broken down in the presence of light

Homolytically

Heterolytically

Both A and B

None of the mentioned

29. Mention the physical properties of alkynes

The boiling and melting points increase as the carbon molecule increases in size.

The density increases as the molecule increase in size.

Both B and A

None of the mentioned.

30. Methane gas is prepared in the laboratory by the decarboxylation of sodium ethanoate by the use of soda lime. True or False

FALSE

Maybe

TRUE

None of the above

31. Mention 3 uses of methane

Methane is used as fuel

Methane is used in the making of carbon black for use in the tire industry and also for printers’ ink

Methane is used in the manufacture of synthesis gas (a mixture of carbon monoxide and hydrogen) when it reacts with steam

All of the above

32. Which of the following is not among the uses of propane?

In the manufacture of nitroalkanes used as a solvent

As a fuel e.g. cooking gas and laboratory gas for heating

In making chloroethane which is needed to make tetraethyl lead for use as an additive in petrol.

None of the mentioned

33. What is the chemical lab confirmation of ethane gas during an experiment?

On bringing a burning splint of wood it burns with a SOOTY flame.

On bringing a burning splint of wood it puts out the flame.

On bringing a burning splint of wood it burns with a VERY sooty flame

None of the above

34. Organic compounds that have the same molecular formula but may have their atoms arranged differently in their molecules are known as

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