Step 1: Arsenic (EN = 2.18) is less electronegative than oxygen (3.44) so arsenic is the central atom.
Step 2: The total number of valence electrons present in AsO43- is:
Group Valence Electrons
As 5A 1 × 5 e– = 5 e–
O 6A 4 × 6 e– = 24 e–
From -3 charge: +3e-
Total: 32 valence e–
Step 3: The Lewis Structure is:
Step 4: There are 4 domains or groups around central element As:
▪ 4 O atoms = 4 domains
• It will need 4 orbitals to accommodate these 4 groups.
Orbitals that can be used by the central atom:
Subshell Total # of orbitals
s _ 1 orbital
p _ _ _ 3 orbitals
d _ _ _ _ _ 5 orbitals
▪ 1 s orbital + 3 p orbitals = 4 orbitals (4 groups)
▪ s p p p = sp3
Draw the Lewis structure of ASO43- showing all lone pairs.
What is the hybridization of the central As atom?
An AsO43- ion is
Identify the molecular geometry of AsO43-.
c) square pyramidal
d) trigonal planar
f) square planar
h) trigonal bipyramidal
i) trigonal pyramidal
What are the approximate bond angles in ASO43-?
a) 90 degrees
b) 109 degrees
c) 120 degrees
d) 180 degrees
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Hybridization concept. You can view video lessons to learn Hybridization. Or if you need more Hybridization practice, you can also practice Hybridization practice problems.
What professor is this problem relevant for?
Based on our data, we think this problem is relevant for Professor Maxwell's class at UCF.