Chemistry - p-Block Elements

Question - 1

Which of the following compound is tribasic acid?

  • A H3PO2
  • B H3PO3
  • C H3PO4
  • D H4P2O7

Question - 2

Among the members of VA group (N,A,As,Sb and Bi),which of the following properties shows an increase as we go down from nitrogen to bismuth?

  • A Electrnegativity
  • B Acidic nature of the pentoxide
  • C Stability of -3 oxidation state
  • D Reducing character of hydrides

Question - 3

Which of the most thermodynamically stable allotropic form of phosporus?

  • A Red
  • B Yellow
  • C White
  • D Black

Question - 4

Which of the folllowing is not known?

  • A Nl3
  • B NCI3
  • C NCI5
  • D SbCI3

Question - 5

The following are some statements related to VA group hydrides,

I.Reducing property increases from NH3

II.Tendency to donate lone pair decreases from NH3 to BiH3

III.Thermal stability of hydrides decreases from NH3 to BiH3

IV.Bond angle of hydrides decreases from NH3 to BiH3

The correct statments are

  • A I,II,III and IV
  • B I,III and IV
  • C I,II and IV
  • D I and IV

Question - 6

A black compound of manganese reacts with a halogen acid to give greenish yellow gas.When excess of this gas reacts with NH3 an un stable trihalide is formed.In this process the oxidation state of nitrogen

  • A -3 to +3
  • B -3 to 0
  • C -3 to +5
  • D 0 to -3

Question - 7

Elements of group-15 form compounds in +5 oxidation state.However,bismuth forms only one well characterised compound in +5 oxidation state.The compound is

  • A Bi2O5
  • B BiF5
  • C BiCI5
  • D Bi2S5

Question - 8

As the number of -OH groups increases in hypophosphoric acid,the acidic strength

  • A increases
  • B decreases
  • C remains nearly same
  • D remains approximately same

Question - 9

Which of the following is the most explosive?

  • A NCI3
  • B PCI3
  • C AsCI3
  • D All of these

Question - 10

In qualitative analysis,when H2S is passesd through an aqueous of salt acidified with dll.HCI ,a black precipitate is obtained.On boiling the precipate with dill.HNO3,it forms a solution of the blue colour.Addtion of excess of aqueous solution of ammonia to this solution gives

  • A deep blue prepitate of Cu(IOH)2
  • B deep blue solution of [Cu(NH3)4]2+
  • C deep blue solution of Cu(NO3)2
  • D deep blue solution of Cu(OH)2 .Cu(NO3)2