A Bond angle calculator is an online tool that helps in predicting the ideal bond angle in a molecule using the popular AXE method.
This calculator is based on the AXE method.
Bond angle calculator
How to calculate the Bond angle?
The bond angle can be calculated using a simple method which is the AXE method.
AXE is a simple formula to represent the number of atoms bonded to the central atom in a molecule and the number of lone pairs present on the central atom.
After finding the number of lone pairs and bonded atoms attached to the central atom, use the VSEPR chart given below to predict the ideal bond angle in a given molecule.
For instance –
If the number of lone pairs (E) on the central atom is 2, and the number of bonded atoms (X) attached to the central atom is 4, then the AXE formula becomes – AX4E2, So, the ideal bond angle for AX4E2 type molecule according to VSEPR chart is 90º.
If the number of lone pairs (E) on the central atom is 2, and the number of bonded atoms (X) attached to the central atom is also 2, then the AXE formula becomes – AX2E2, So, the ideal bond angle for AX2E2 type molecule according to VSEPR chart is <109.5º (104.5º).
Look at the VSEPR chart of the bond angle given below with all the necessary data.
VSEPR notation
Bond pairs
Lone
pairs
Ideal electronic geometry
Molecular geometry
Ideal Bond angles
Examples
AX2
2
0
Linear
Linear
180°
BeCl2, CO2
AX3
3
0
Trigonal
planar
Trigonal
planar
120°
BF3
AX2E
2
1
Trigonal
planar
Bent
<120° (119°)
SO2
AX4
4
0
Tetrahedral
Tetrahedral
109.5°
CH4, CCl4
AX3E
3
1
Tetrahedral
Trigonal pyramidal
<109.5° (107.5°)
NH3
AX2E2
2
2
Tetrahedral
Bent
<109.5° (104.5°)
H2O
AX5
5
0
Trigonal bipyramidal
Trigonal bipyramidal
90°, 120°
PCl5
AX4E
4
1
Trigonal bipyramidal
Seesaw
ax–ax 180° (173.1°),
eq–eq 120° (101.6°),
ax–eq 90°
SF4
AX3E2
3
2
Trigonal bipyramidal
T-shape
<90° (87.5°), <180° (175°)
ClF3
AX2E3
2
3
Trigonal bipyramidal
Linear
180°
XeF2
AX6
6
0
Octahedral
Octahedral
90°, 180°
SF6
AX5E
5
1
Octahedral
Square pyramidal
<90° (84.8º)
BrF5
AX4E2
4
2
Octahedral
Square Planar
90°
XeF4
Now, the question arises how will you find the number of lone pairs on the central atom of the molecule. For that, the best way to predict the number of lone pairs and bond pairs in the molecule is using a lewis structure.
A bond angle calculator is an online tool to predict the bond angle in a molecule according to VSEPR (AXE) notation.
How can you predict bond angle using VSEPR notation?
You can use a Bond angles chart to predict the ideal bond angle based on VSEPR notation. The VSEPR notation is represented by the AXE formula where A denotes the central atom, X denotes the number of bonded atoms to the central atom, and E denotes the number of lone pairs on the central atom.
Vishal Goyal is the founder of Topblogtenz, a comprehensive resource for students seeking guidance and support in their chemistry studies. He holds a degree in B.Tech (Chemical Engineering) and has four years of experience as a chemistry tutor. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. A passion for sharing knowledge and a love for chemistry and science drives the team behind the website. Let's connect through LinkedIn: https://www.linkedin.com/in/vishal-goyal-2926a122b/
Topblogtenz is a website dedicated to providing informative and engaging content related to the field of chemistry and science. We aim to make complex subjects, like chemistry, approachable and enjoyable for everyone.
