Chemistry Class 11

Which of the following is an example of super octet molecule ?

• ClF₃

• PCl₅

• IF₇

• all of the above

Which of the following substances has the highest melting point?

• NaCl

• KCl

• MgO

• BaO

What is the valency of carbon in CO₃^2- ?

• 2

• 3

• 4

• -3

In allene structure, three carbon atoms are joined by

• Three sigma bonds and three pi bonds

• Two sigma bonds and one pi- bond

• Two sigma bonds and two pi bonds

• Three pi bonds only

The nodal plane in the π-bond of ethene is located in

• The molar plane

• A plane parallel to the molecular plane

• A plane perpendicular to the molecular plane which bisects the carbon-carbon sigma bond at right angle

• A plane perpendicular to the molecular plane which contains the carbon-carbon σ-bond.

Which one of the following molecules has the smallest bond angle?

• NH₃

• PH₃

• H₂Se

• H₂S

In terms of polar character, which of the following order is correct?

• NH₃ < H₂O < HF < H₂S

• H₂S < NH₃ < H₂O < HF

• H₂O < NH₃ < H₂S < HF

• HF < H₂O < NH₃ < H₂S

Which of the following pair of molecules will have permanent dipole moment for both members?

• NO₂ & CO₂

• NO₂ & O₃

• SiF₄ & CO₂

• SiF₄ & NO₂

Two hybrid orbitals have a bond angle of 120°. The percentage of s character in the hybrid orbital is nearly

• 25%

• 33%

• 50%

• 66%

The hybrid state of C atom in C₂H₂ is same as that of carbon in

• C₂H₆

• CO₂

• BENZENE

• C (diamond)