Which one of the following is an amine hormone?

• Thyroxine

• Oxypurin

• Insulin

• Progesterone

42.

Which one of the following statements is not true? 

• In vulcanization, the formation of sulphur bridges between different chains make rubber harder and stronger

• Natural rubber has the trans-configuration at every double bond

• Buna-S is a copolymer of butadiene and styrene

• Natural rubber is a 1,4 polymer of isoprene

In DNA. the complimentary bases are 

• Adenine and thymine; guanine and cytosine

• Adenine and thymine; guanine and uracil

• Adenine and guanine, thymine: Guanine and uracil

• Uracil and adenine; cytosine and guanine

Acetophenone when reacted with a base, C₂H₅ONa, yields a stable compound which has the structure

The relative reactivities of acyl compounds towards of nucleophilic substitution are in the order of 

• Acyl chloride> Acid anhydride> Ester> Amide

• Ester > Acyl chloride> Amide > Acid anhydride

• Acid anhydride > Amide > Ester> Acyl chloride

• Acyl chloride > Ester > Acid anhydride > Amide

Which one of the following is most reactive towards electrophilic attack? 

In an S_N2  substitution reaction of the type which  one of the followings has the highest relative rate?

• CH₃-CH₂-CH₂Br

• CH₃-CH(CH₂)-CH₂Br

• CH₃C(CH₃)₂CH₂Br

• CH₃CH₂Br

In a reaction of aniline, a coloured product C was obtained.