Dry ice is

• solid CO₂

• solid camphor

• solid SO₂

• solid NO₂

Which does not give a precipitate with AgNO₃ solution?

• [Co(NH₃)₆]Cl₃

• [Co(NH₃)₅Cl]Cl₂

• [Co(NH₃)₄Cl₂]Cl

• [Co(NH₃)₃Cl₃]

Total volume of atoms present in a face centred cubic unit cell of a metal is (r is atomic radius)

• $\frac{16}{3} {\mathrm{\pi r}}^3$

• $\frac{20}{3}{\mathrm{\pi r}}^3$

• $\frac{24}{3}{\mathrm{\pi r}}^3$

• $\frac{12}{3}{\mathrm{\pi r}}^3$

Sodium formate on heating gives

• oxalic acid and H₂

• sodium oxalate and H₂

• sodium oxalate

• CO₂ and caustic soda

Stereisomers differ in

• configuration

• conformation

• they do not differ

• none of the above

IUPAC name of the following compound

• N, N- dimethylcyclopropane carboxamide

• N-methylcyclopropanamide

• cyclopropionamide

• None of the above

Gold number is associated with

• amount of gold

• protective colloids

• purple of cassius

• electrophoresis

28.

Pure silicon doped with phosphorus is a 

• metallic conductor

• insulator

• n-type semiconductor

• p-type semiconductor

The product of following reaction is

2CH₃MgBr + CH₂O $\to$

• CH₃OH

• C₂H₅OH

• CH₄

• C₂H₆

Noble gases are used in discharge tubes to give different colours. Reddish-orange glow is due to

• Ar

• Ne

• Xe

• Kr