NEET Chemistry The p-Block Elements (XII) Questions Solved

Which of the correct sequence in the following properties? For the correct order mark (T) and for the incorrect order mark (F) :

(a)  Lewis acidity order : SiF4<SiCl4<SiBr4<SiI4 

(b) Melting point : NH3>SbH3>AsH3>PH3

(c) Boiling point : NH3>SbH3>AsH3>PH3

(d) Dipole moment order : NH3>SbH3>AsH3>PH3

(a) FTFT        (b) TFTF        (c) FFTT         (d) FFTF

(a)     (F); As the size of halogen atom increases crowding on Si atom will

          increase, hence, tendency of attack of Lewis base decreases.

(b)     (T); M.P. of NH3 is higgest due to intermolecular H-bonding in it.

          Next lower M.P. will be of SbH3 followed by AsH3 due to high mol.wt.

          of SbH3.

(c)      (F); M.P. and M.P. of increase from PH3 to SbH3 via AsH3 due to 

          increase  in mol. wt. NH3 does not follow this trend due to inter 

          molecular H-bonding.

(d)      (T); Value of bond moment decreases.




Difficulty Level:

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