Question

the shape of Nh4+ is
A.sea-saw
B.tetrahedeal
C.pyramidal
D.linear

Answer 1

Total valence electrons = 5+ 4 - 1= 8 , each of the four hydrogen atoms have doublets around it and hence 8-8=0 . So lone pairs on central atom=0 , bond pairs on central atom= 4, total pairs on central atom=4 Hybridisation of central atom is sp^3. Geometry is tetrahedral, and since no pairs on central atom , the shape is also tetrahedral. b) 5+2+1=8, 8-4=4, there are two lone pairs and two bond pairs on central atom N, Hence the hybridisation of central atom is sp^3 . The geometry is tetrahedral and since it contains two lone pairs which do not contribute to shape , the shape is bent. c) 4+18+2=24, for each O atom around C, there is octet, hence 24-24=0, this gives no lone pairs and three bond pairs around central atom C, the hybridisation of central atom is sp^2, and geometry is trigonal planar, and since no lone pairs on central atom, the shape of the molecule is also trigonal planar. d) 7+14+2= 23, since the single electron always stays in atomic orbital, this gives total valence electrons 22. 22-16=6 , the central atom contains 3 lone pairs and two bond pairs. Total pairs on central atom is five. The central atom undergoes sp3d hybridisation. Hence , the geometry of the molecule is trigonal bipyramid and since there are three lone pairs which are always oriented along equitorial positions to reduce repulsions, the shape of the molecule T shaped. Repulsions between lone pairs are important at 90degrees or below and unimportant above 90 degrees.



Molecule == Electron Domain === Molecular Geometry 

NH4 + ==== Tetrahedral ====== Tetrahedral 
NH2 - ==== Tetrahedral ======= Bent 
CO3 2- === Trigonal Planar ==== Trigonal Planar 
ICl2 - ==== Trigonal Bipyramidal == Linear 

Answer 2

♠ ANSWER :

❇ The shape of NH 4 + is TETRAHEDRAL.