Certain crystals produce electric signals on application of perssure. This phenomenon is called :

• pyroelectricity

• ferroelectricity

• piezoelectricity

• ferrielectricity

The element ₉₀Th²³² belong to thorium series. Which of the following will act as the end product of the series?

• ₈₂Pb²⁰⁸

• ₈₂Bi²⁰⁹

• ₈₂Pb²⁰⁶

• ₈₂Pb²⁰⁷

The half-life of a first order reaction having rate constant k =1.7 x10^-5 s^-1 is :

• 12.1 h

• 9.7 h

• 11.3 h

• 1.8 h

Aspirin is :

• antipyretic

• tranquilizer

• narcotic

• anaesthetic

In Williamson's synthesis, ethoxyethane is prepared by :

• passing ethanol over heated alumina

• heating sodium ethoxide with ethyl bromide

• treating ethyl alcohol with excess of H₂SO₄ at 430-440 K

• heating ethanol with dry Ag₂O

HCHO reacts with CH₃MgI to give:

• CH₃CH₂OH

• CH₃OH

• CH₃CH₂I

• CH₃I

reacts with acetic acid in presence of Hg²⁺ to give:

• 

• 

• 

• None of these

38.

Which among the following is strongest acid ?

• H(ClO)O₂

• H(ClO)O₃

• H(ClO)O

• H(ClO)

Which of the following amino acid is optically inactive?

• Phenyl alanine

• Glycine

• Glutamic acid

• Asparagine

Glucose has difference from fructose in that it:

• does not undergo hydrolysis

• gives silver mirror with Tollen's reagent

• monosaccharide

• none of the above