Sample/practice exam 2015, questions PDF

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Organic Chemistry General Practise Questions ...

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Question 1 Which of the following cannot react as a nucleophile? a) CH3NH2 b) (CH3)2NH c) (CH3)3N d) (CH3)4N+

Question 2 Which of the following cannot react as a nucleophile? a) CH3OH b) CH3Oc) CH3O+H2 d) CH3OCH3

Question 3 Which of the following cannot react as a nucleophile? a) H2C=CH2 b) BH3 c) H2C=NH d) CH3CH2SH

Question 4 Which of the following is not a typical electrophile? a) Cl2 b) HBr c) (CH3)4N+ d) Br2

Question 5 Which of the following reactions is an elimination? a)

b) c)

d)

Question 6 Which of the following reactions is a substitution? a)

b) c)

d)

Question 7 Which of the following reactions is an addition? a)

b) c)

d)

Question 8 The following stepwise reactions comprise a mechanism for the acid-catalysed hydrolysis of an ester. Which step of (a)-(d) is an addition?

a) Step (a) b) Step (b) c) Step (c) d) Step (d)

Question 9 The following stepwise reactions comprise a mechanism for the acid-catalysed hydrolysis of an ester. Which step of (a)-(d) is an elimination?

a) Step (a) b) Step (b) c) Step (c) d) Step (d)

Question 10

Which of the following can react as a nucleophile? a) (CH3)3B b) (CH3)3CH c) (CH3)3N d) (CH3)3O+

Question 11 Which of the following does not normally react as a nucleophile? a) (CH3)2O b) (CH3)2OH+ c) CH3CH2OH d) CH3CH2O-

Question 12 Which of the following reacts most readily as an electrophile? a) HBr b) CH3Br c) CH3OH d) (CH3)4N+

Question 13 Which of the following normally reacts as an electrophile? a) (CH3)3CH b) H2C=CH2 c) (CH3)2O d) CH3Cl

Question 14 Which of the following can react readily either as a nucleophile or as an electrophile? a) (CH3)3B b) (CH3)2O

c) CH3CO2H d) H2C=CH2

Question 15 Which of the following statements is wrong? a) The higher the energy of its HOMO, the more reactive a nucleophile will usually be. b) The higher the energy of its LUMO, the more reactive an electrophile will usually be. c) In an exothermic reaction, the enthalpy of the product(s) is lower than that of the reactant(s). d) The equilibrium constant of an endergonic reaction is smaller than 1.

Question 16 Which of the following statements is wrong? a) It is not necessary for a nucleophile to have an unshared electron pair. b) A species can react as an electrophile if it contains an atom (other than hydrogen) with an incomplete valence octet. c) A species can react as an electrophile, even if it has one or more unshared electron pairs. d) Any species bearing a lone pair can normally react as a nucleophile.

Question 17

Where is the use of a curly arrow wrong in the following reaction sequence? Specify by (a)(d).

a) Stage (a) b) Stage (b) c) Stage (c) d) Stage (d)

Question 18 Where is the use of a curly arrow wrong in the following reaction sequence? Specify by (a)(d).

a) Stage (a) b) Stage (b) c) Stage (c) d) Stage (d)...