Grand Test Chemistry ( Hydrocarbons)
Sindh Education Foundation, Government of Sindh Chemistry Chemistry Official @chemistry model
Section "A"
1. The reason that benzene burn with soot is:
a) Aromaticity
b) Inflammability
c) High resonance energy
d) High carbon contents
2. Catechol and Resorcinol are:
a) chain isomers
b) metamers
c) position isomers
d) functional isomers
3. The hybridization of carbon in benzene is:
a) sp
b) sp²
c) sp³
d) sp³d²
4. The formula of saturated hydrocarbon is C3H6 it should be:
a) propane
b) propene
c) cyclopropane
d) propyne
5. The dehydration of alcohol gives:
a) Alkene
b) alkane
c) alkyne
d) benzene
6. The final products obtained when HBr is added to propyne molecule:
a) 1,2- dibromo propane
b) 1,1- dibromo propane
c) 2,2- dibromo propane
d) 2,3- dibromo propane
7. Alkenes are also called:
a) proteins
b) paraffins
c) acetylene
d) Olefins
8. Welding gas among the following is:
a) ethyne
b) ethane
c) ethene
d) methisomers
The characteristic reaction of benzene is:
a) electrophilic addition reaction
b) nucleophilic addition reaction
c) electrophilic substitution reaction
d) elimination reaction.
10. Glucose and fructose are:
a) position isomers
b) metamers
c) chain isomers
d) functional isomers
11. What is the general formula for cycloalkenes ?
A) CnH2n+2 B) CnH2n
C) CnH2n-2 D) Cn H2n-4
12. Which of the following about Alkenes is false:
A) Alkenes are unsaturated hydrocarbons.
B) Alkenes are more reactive than alkanes.
C) Alkenes are less dense than alkanes.
D) Alkenes have trigonal plannar geometry around the double bond.
13. The incorrect statements about aromatic hydrocarbons is:
A) Aromatic hydrocarbons are highly reactive.
B) Aromatic hydrocarbons are highly stable.
C) Aromatic hydrocarbons have alternating double bonds.
D) Aromatic hydrocarbons have a planar, rings shaped molecule.
14. The reaction between an Alkane and a halogen in the presence of light will be:
A) Addition reaction
B) Substitution reaction
C) Elimination reaction
D) Rearrangement reaction
15. Which of the following statements about the stability of Alkenes is TRUE?
A) The stability of Alkenes increases with increasing substitution of the double bond.
B) The stability of Alkenes decreases with increasing substitution of the double bond.
C) The stability of Alkenes is unaffected by the substitution of the double bond.
D) The stability of Alkenes is determined by the molecular weight of the Alkenes.
16. The reaction which involves the conversion of an alkane into an alkyl halide is:
A) Halogenation
B) Dehydrogenation
C) Hydration
D) Reforming
17. What is the result of the reaction between an alkyne and a strong base?
A) Deprotonation to form an alkynide ion
B) Protonation to form an alkyl halide
C) Hydrolysis to form an alcohol
D) Hydration to form a ketone
18. Which of the following statements about the reactivity of Alkenes is TRUE?
A) Alkenes are less reactive than alkanes.
B) Alkenes are more reactive than alkanes.
C) Alkenes are equally reactive as alkanes.
D) The reactivity of Alkenes is unaffected by the substitution of the double bond.
19. Which of the following reactions is an example of an electrophilic addition reaction?
A) Reaction between an alkene and a strong base
B) Reaction between an alkene and a halogen
C) Reaction between an alkane and a strong acid
D) Reaction between an alkyne and a reducing agent
20. What is the result of the reaction between an alkene and a strong acid( e.g HBr) ?
A) Addition of the acid to the double bond
B) Substitution of the acid for a hydrogen atom
C) Elimination of a hydrogen atom to form a new double bond
D) Rearrangement of the Alkenes to form a new compound.
21. Which of the following reactions is an example of a radical substitution reaction?
A) Reaction between an alkane and a halogen
B) Reaction between an alkene and a strong base
C) Reaction between an alkyne and a reducing agent
D) Reaction between an aromatic hydrocarbon and a strong acid
22. Which of the following statements about the reactivity of aromatic hydrocarbons is TRUE?
A) Aromatic hydrocarbons are highly reactive due to the presence of a triple bond.
B) Aromatic hydrocarbons are highly reactive due to the presence of a double bond.
C) Aromatic hydrocarbons are relatively unreactive due to the delocalization of electrons in the ring.
D) Aromatic hydrocarbons are highly reactive due to the presence of a strong acid.
23. Which of the following reactions is an example of a Friedel-Crafts alkylation reaction?
A) Reaction between an aromatic hydrocarbon and a strong acid
B) Reaction between an aromatic hydrocarbon and a halogen
C) Reaction between an aromatic hydrocarbon and an alkyl halide
D) Reaction between an aromatic hydrocarbon and a strong base
24. Which of the following statements about the reactivity of aromatic hydrocarbons is true:
A) Aromatic hydrocarbons are highly reactive due to the presence of a triple bond.
B) Aromatic hydrocarbons are highly reactive due to the presence of a double bond.
C) Aromatic hydrocarbons are relatively unreactive due to the delocalization of electrons in the ring.
D) Aromatic hydrocarbons are highly reactive due to the presence of a strong acid.
25. Which of the following types of hydrocarbons is characterized by a planar, ring-shaped molecule with alternating double bonds?
A) Alkanes
B) Benzene
C) Alkenes
D) Alkynes
26. What is the name of the reaction that involves the conversion of an alkane into an alkene through the use of high temperatures and pressures?
A) Cracking
B) Reforming
C) Hydrogenation
D) Dehydrogenation
27. Which of the following statements about the reactivity of alkenes is true:
A) Alkenes are less reactive than alkanes due to the presence of a double bond.
B) Alkenes are more reactive than alkanes due to the presence of a double bond.
C) Alkenes are equally reactive as alkanes due to the presence of a double bond.
D) The reactivity of alkenes is unaffected by the substitution of the double bond.
28. Which of the following types of hydrocarbons is characterized by a high degree of unsaturation :
A) Alkanes
B) Alkenes
C) Alkynes
D) Benzene
29. What is the name of the reaction that involves the conversion of an alkane into an alkene through the use of a catalyst?
A) Cracking
B) Reforming
C) Hydrogenation
D) Dehydrogenation
30. Which of the following statements about the reactivity of aromatic hydrocarbons is TRUE?
A) Aromatic hydrocarbons are highly reactive due to the presence of a triple bond.
B) Aromatic hydrocarbons are highly reactive due to the presence of a double bond.
C) Aromatic hydrocarbons are relatively unreactive due to the delocalization of electrons in the ring.
D) Aromatic hydrocarbons are highly reactive due to the presence of a strong acid.
31. What is the result of the reaction between an alkyne and a strong reducing agent?
A) Reduction of the alkyne to an alkene
B) Reduction of the alkyne to an alkane
C) Oxidation of the alkyne to a ketone
D) Oxidation of the alkyne to an aldehyde
*Section "B"*
(Attempt any FOUR questions)
1) Draw and explain orbital structure of ethane and write methods of its preparation.
2) What are electrophiles? Give the reaction mechanism of friedal craft alkylation and sulphonation of benzene.
3) Define isomerism give its types with examples.
4) (a) "Acetylene shows acidic properties " Give two reactions to justify this statement.
(B) Give two reactions in which benzene ring is not retained.
5). Give the mechanism of free radical substitution reaction between methane and chlorine in the presence of sunlight.
6). Alkanes are generally referred as parafins due to their less reactivity. Why are they stable toward chemical reactions.
*Section "C"* Attempt any one question.
1). (a) What is meant by ortho, para and Mata directing groups. Explain the influence of substituents of benzene to incoming electrophile.
(b) Explain the following with suitable examples:
I) Optical isomers
II) Geometrical isomers.
*OR*
2).(a) Describe the molecular orbital structure of benzene.
(b) *Write the equations for the following chemical processes:*
I) Ethene is burnt in air in the presence of per acetic acid.
III) 1,2-dibromo butane is heated with alcoholic potassium hydroxide.
III) Ethylene is heated at high temperature and pressure.
IV) 1,1,2,2-tetra bromo ethane is heated with zinc Powder.
V) Propene is reacted with HBr.
VI) Cleavage of an alkene by ozone in the presence of zinc.
VII) Addition of chlorine to benzene ring in the presence of sunlight.
VIII) Hydration of ethyne in the presence of sulphuric acid and mercurous acid
Comments
Post a Comment