31.

Which of the following organo - silicon compound on hydrolysis will give a three dimensional silicone ?

• R₃SiCl

• RSiCl₃

• SiCl₄

• R₂SiCl₂

Which colourless gas evolves when NH₄Cl reacts with zinc in a dry battery ?

• NH₃

• N₂

• H₂

• Cl₂

Oxidation number of sulphur in H₂S₂O₈ is :

• +6

• +8

• +21

• +7

Reason of passively of iron is :

• Fe₂O₃

• Fe₃O₄

• FeO

• Fe₂O₄ ^. 3H₂O 

Half-life of radioactive substance is 4 days . Amount of the substance decayed in two days is :

• $\frac{1}{\sqrt{2}}$

• 1 - $\frac{1}{\sqrt{2}}$

• 20 %

• $\frac{1}{8}$

Iodine is tested by the following reagent :

• starch

• urea

• glucose

• glycerol

Half-life pf a radioactive element is :

• 0.693

• $\frac{1}{0.693}$

• $\frac{0.693}{\mathrm{k}}$

• $\frac{\mathrm{k}}{0.693}$

Fuel used in nuclear reactor is :

• plutonium

• thorium

• radium

• deuterium

Which gives nucleophilic addition most easily :

• CH₃CHO

• CH₃CH₂CHO

• (CH₃)₂CHCHO

• HCHO

Reagent used to extract silver from Ag₂S is :

• NaCN

• NaCN in presence of O₂

• NaCl

• AgNO₃