Question

TeF5- anion.

a) How many valence electrons does Te have?

b) How many valence electrons does F have?

c) Write the Lewis structure of TeF5 - anion:

d) Assign formal charges to each atom in the Lewis structure of the TeF5 - anion.

e) What is the hybridization of the orbitals on the central atom in the anion TeF5 -?

d) Predict the molecular geometry of the TeF5 - anion:

Answer 1

Solution:

a) There are 6 valence electrons present in Te

for the valence shell configuration 5s²5p⁴

b) There are 7 valence electrons are present in F

for the valence shell configuration 2s²2p⁵

c) This is the Lewis Structure of TeF₅^- in which there are 6 electrons are there as 3 lone pairs on each F atom.

d) This is the Lewis structure of TeF₅^- with formal charge

e) No of electrons from Te= 6

No of electrons from 5 F is = 5

From negative charge = 1

So there are a total of 12 electrons i.e. 6 electron pairs indicating sp³d² hybridization. Out of 6 electron pairs, 5 are bond pairs, and the remaining one electron pair stay as a lone pair.

e) 6 electron pairs in TeF₅^- indicating sp³d² hybridization that have octahedral in geometry but since there is a lone pair which occupy the axial position so the actual shape of TeF₅^- will be square pyramidal in geometry.