The p-Block Elements

Which one of the following is not true at room temperature and pressure?

• P₄O₁₀ is white solid

• SO₂ is a colourless gas

• SO₃ is a colourless gas

• NO₂ is a brown gas

An element belongs to group 15 and third period of the Periodic Table. Its electronic configuration wil be

• 1s²2s²2p³

• 1s²2s²2p⁴

• 1s²2s²2p⁶3s²3p³

• 1s²2s²2p⁶3s²3p²

In the brown ring complex [Fe(H₂O)₅(NO)]SO₄, nitric oxide behaves as

• NO⁺

• neutral NO molecule

• NO^-

• NO^2-

Platinum, palladium and iridium are called noble metals because

• Alfred Nobel discovered them

• they are shining lustrous and pleasing to look at

• they are found in native state

• they are inert towards many common reagents

NO₂ is not obtained on heating

• AgNO₃

• KNO₃

• Cu(NO₃)₂

• Pb(NO3)2

A solution of KMnO₄ is reduced to a various products depending upon its pH. At pH<7, it is reduced to a colourless solution (A), at pH =7 it forms a brown precipitate (B) and at pH> 7, it gives a green solution (C).(A), (B) and (C) are

• A	B	C
  Mn2+	MnO2	${\mathrm{MnO}}_4^{2-}$

• A	B	C
  MnO2	Mn2+	${\mathrm{MnO}}_4^{2-}$

• A	B	C
  ${\mathrm{MnO}}_4^{2-}$	Mn2+	MnO2

• A	B	C
  Mn2+	${\mathrm{MnO}}_4^{2-}$	MnO2

Which of the following reactions depict the oxidising behavior of H₂SO₄?

• $2{\mathrm{PCl}}_5 + {\mathrm{H}}_2{\mathrm{SO}}_4 \to 2{\mathrm{POCl}}_3 + 2\mathrm{HCl} +{\mathrm{SO}}_2{\mathrm{Cl}}_2$

• $2\mathrm{NaOH} + {\mathrm{H}}_2{\mathrm{SO}}_4 \to {\mathrm{Na}}_2{\mathrm{SO}}_4 + 2{\mathrm{H}}_2\mathrm{O}$

• $\mathrm{NaCl} + {\mathrm{H}}_2{\mathrm{SO}}_4 \to {\mathrm{NaHSO}}_4 + \mathrm{HCl}$

• $2\mathrm{HI} +{\mathrm{H}}_2{\mathrm{SO}}_4 \to {\mathrm{I}}_2 + {\mathrm{SO}}_{2 }+ 2{\mathrm{H}}_2\mathrm{O}$

Which two sets of reactants best represents the amphoteric character of Zn(OH)₂?

Set I - Zn(OH)₂(s) and OH^- (aq)

Set II - Zn(OH)₂(s) and H₂O (I)

Set III - Zn(OH)₂ (s) and H⁺ (aq)

Set IV - Zn(OH)₂(s) and NH₃ (aq)

• III and II

• I and III

• IV and I

• II and IV

An organic compound having carbon, hydrogen and sulphur contains 4% of sulphur. The minimum molecular weight of
the compound is

• 200

• 400

• 600

• 800

Which has the smallest size?

• Na⁺

• Mg²⁺

• Al³⁺

• P⁵⁺