51.

CH₃CO₂C₂H₅ on reaction with sodium ethoxide in ethanol gives A, which on heating in the presence of acid gives B. Compound B is

• CH₃COCH₂COOH

• CH₃COCH₃

• 

• CH₂=C(OC₂H₅)₂

Among the following which one does not act as an intermediate in Hofmann rearrangement?

• RNCO

• RCO$\stackrel{..}{\mathrm{N}}$

• RCO$\stackrel{..}{\mathrm{N}}$HBr

• RNC

Pyridine is less basic than triethylamine because

• pyridine has aromatic character

• nitrogen in pyridine is sp² hybridised

• pyridine is a cyclic system

• in pyridine, lone pair of nitrogen is delocalised

Which one of the following biomolecules is insoluble in water?

• α-keratin

• haemoglobin

• ribonuclease

• adenine

Correct configuration of the following is

• 1S, 2S

• 1S, 2R

• 1R, 2S

• 1R, 2R

Which one of the following statements is true for protein synthesis (translation)?

• Amino acids are directly recognized by m-RNA.

• The third base of the codon is less specific.

• Only one codon codes for an amino acid.

• Every t-RNA molecule has more than oneamino acid attachment.

CH₆CO₅NHCH₃ can be converted into C₆H₅CH₂NHCH₃ by

• NaBH₄

• H₂-Pd/C

• LiAl₄

• Zn-Hg/HCl

Assertion : Rate of hydrolysis of methyl chloride to methanol is higher in DMF than in water.

Reason : Hydrolysis of methyl chloride follows second order kinetics.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : t-Butyl methyl ether is not prepared by the reaction of t-butyl bromide with sodium methoxide.

Reason : Sodium methoxide is a strong nucleophile.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Maltose is a reducing sugar which gives two moles of D-glucose on hydrolysis.

Reason : Maltose has a 1,4-β-glycosidic linkage.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.