The p-Block Elements

The orange solid on heating gives a colourless gas and a green solid which can be reduced to metal by aluminium powder. The orange and the green solids are, respectively

• NH₄Cr₂O₇ and Cr₂O₃

• Na₂Cr₂O₇ and Cr₂O₃

• K₂Cr₂O₇ and CrO₃

• (NH₄)₂CrO₄ and CrO₃

Which of the following oxides is strongly basic?

• TI₂O

• B₂O₃

• Al₂O₃

• Ga₂O₃

Which of the following oxide is amphoteric?

• SnO₂

• CaO

• SiO₂

• CO₂

Match the following.

• (A)   (B)   (C)   (D)

  IV     V      II      I

• (A)   (B)   (C)   (D)

  IV      V      I      II

• (A)   (B)   (C)   (D)

  IV      I     III     II

• (A)   (B)   (C)   (D)

  II      V     IV      I

Diamond is hard because

• all the four valence electrons are bonded to each carbon atoms by covalent bonds

• it is a giant molecule

• it is made up of carbon atoms

• it cannot be burnt

The decomposition temperature is maximum for

• MgCO₃

• CaCO₃

• BaCO₃

• SrCO₃

Which one of the following reacts with glass?

• H₂SO₄

• HF

• HNO₃

• K₂Cr₂O₇

Monosilane on coming in contact with air bums with a luminous flame producing vortex rings. These rings are of

• SiO₂

• SiO

• Si

• H₂SiO₃

Carborundum is

• SiC

• Al₂O₃$·$H₂O

• Al₂(SO₄)₃

• AlCl₃

Which of the following does not contain silicon?

• Kaoline

• Agate

• Ruby

• Quartz