Practice Pakistan's most useful MCQs for competitive exams

Which alkyl halide out of the following may follow both SN1 and SN2 mechanism ?

• (A)  CH3-X
• (B)  (CH3)3 C-CH2 – X
• (C)  (CH3)2 CH – X
• (D)  (CH3)3 C – X

Answer

Submitted By :Ali Uppal

Which one is not a nucleophile ?

• (A)  C2H5O-
• (B)  SCN-
• (C)  NH3
• (D)  H3C+

Answer

Submitted By :Ali Uppal

Which alkyl halide has the highest reactivity for a particular alkyl group ?

• (A)  R-F
• (B)  R-C
• (C)  R-Br
• (D)  R-I

Answer

Submitted By :Ali Uppal

50% inversion of configuration of molecules take place in a___________________?

• (A)  E1 – reaction
• (B)  E2 – reaction
• (C)  SN1 – reaction
• (D)  SN2 – reaction

Answer

Submitted By :Ali Uppal

The best method of preparation of alkyl halides is a reaction of alcohol with__________________?

• (A)  Zn / HCI
• (B)  SOCl2 / Pyridine
• (C)  PCI3
• (D)  PCI5

Answer

Submitted By :Ali Uppal

In primary alkyl halides the halogen atom is attached to a carbon which is further attached to how many carbon atoms__________________?

• (A)  two
• (B)  three
• (C)  one
• (D)  four

Answer

Submitted By :Ali Uppal

Which one of the following molecules does not form alcohol when reacts with Grignard reagent ?

• (A)  formaldehyde
• (B)  acetaldehyde
• (C)  propanone
• (D)  carbondioxide

Answer

Submitted By :Ali Uppal

K2Cr2O7/H2SO4 generate____________________?

• (A)  Oxygen
• (B)  Hydrogen
• (C)  Nascent oxygen[O]
• (D)  Nascent hydrogen[H]

Answer

Submitted By :Ali Uppal

The process of fermentation of starch involve many enzymes the sequence of enzymes used are____________________?

• (A)  Diastase-maltase-zymase
• (B)  Zymase-maltase-diastase
• (C)  Maltase-diastase-zymase
• (D)  Diastase-zymase-maltase

Answer

Submitted By :Ali Uppal

The residue obtained after the crystallization of sugar from concentrated sugar cane juice is called__________________?

• (A)  Mother liquor
• (B)  Filterate
• (C)  Extract
• (D)  Molasses

Answer

Submitted By :Ali Uppal