⚡ Dipole Moment Calculator
Calculate electric dipole moment
Enter the magnitude of one charge (the other is -q). Example: 1.6 × 10⁻¹⁹ C
Distance between the two opposite charges
How to Use This Calculator
Enter Charge Magnitude
Input the magnitude of one of the charges in Coulombs. The dipole consists of two opposite charges (+q and -q), so enter the magnitude of either charge.
Enter Separation Distance
Input the distance between the two opposite charges in meters. This is the vector distance from the negative charge to the positive charge.
Calculate
Click the "Calculate Dipole Moment" button to get the dipole moment in Coulomb-meters (C⋅m) or Debye units.
Formula
p = q × d
Where:
- p = Electric Dipole Moment (Coulomb-meters, C⋅m)
- q = Charge Magnitude (Coulombs, C)
- d = Separation Distance (meters, m) - from negative to positive charge
Alternative Unit (Debye):
1 Debye (D) = 3.336 × 10⁻³⁰ C⋅m
Example Calculation:
For charges of ±1.6 × 10⁻¹⁹ C separated by 1 × 10⁻¹⁰ m (typical atomic scale):
p = (1.6 × 10⁻¹⁹) × (1 × 10⁻¹⁰)
p = 1.6 × 10⁻²⁹ C⋅m
p = 4.8 D (Debye)
Note: The dipole moment is a vector quantity pointing from the negative charge to the positive charge.
About Dipole Moment Calculator
The Dipole Moment Calculator determines the electric dipole moment of a system consisting of two equal but opposite charges separated by a distance. The dipole moment is a vector quantity that characterizes the strength and direction of the dipole and is fundamental in understanding molecular polarity, intermolecular forces, and the behavior of molecules in electric fields.
When to Use This Calculator
- Chemistry: Calculate dipole moments of molecules to predict polarity and intermolecular interactions
- Physics: Analyze electric field effects on dipoles and dipole interactions
- Material Science: Understand dielectric properties and polarization in materials
- Molecular Modeling: Characterize molecular structure and charge distribution
- Academic Study: Solve problems involving electric dipoles and their behavior in fields
Why Use Our Calculator?
- ✅ Simple Calculation: Instantly calculate dipole moments from charge and distance
- ✅ Scientific Notation: Handles atomic and molecular scale values
- ✅ Accurate Results: Precise calculations for molecular and atomic dipoles
- ✅ Free Tool: No registration or payment required
- ✅ Educational: Learn about molecular polarity and dipole interactions
Common Applications
Molecular Polarity: Calculate dipole moments to predict whether molecules are polar or nonpolar, which affects solubility, boiling points, and intermolecular forces. Water (H₂O) has a dipole moment of about 1.85 D, making it highly polar.
Intermolecular Forces: Understand dipole-dipole interactions between molecules, where molecules with larger dipole moments have stronger attractions, affecting physical properties like melting and boiling points.
Dielectric Materials: Analyze how dipole moments contribute to the dielectric constant of materials, which determines how materials respond to electric fields and store electrical energy.
Tips for Best Results
- The dipole moment points from the negative charge to the positive charge
- Larger charge separation or larger charges result in larger dipole moments
- For molecules, dipole moment depends on both bond polarity and molecular geometry
- Use consistent units: charge in Coulombs, distance in meters
- For molecular dipoles, typical values range from 0 to about 11 D
Frequently Asked Questions
What is a dipole moment?
A dipole moment is a measure of the separation of positive and negative charges in a system. It's a vector quantity with magnitude equal to the product of charge and separation distance, pointing from negative to positive charge.
What are typical dipole moment values?
For molecules, dipole moments range from 0 D (nonpolar, like CO₂) to about 11 D for very polar molecules. Water has 1.85 D, ammonia has 1.47 D, and HCl has about 1.08 D. Atomic dipoles are much smaller, typically 10⁻³⁰ C⋅m.
How does dipole moment relate to molecular polarity?
A molecule with a non-zero dipole moment is polar. Larger dipole moments indicate greater polarity. However, molecular geometry matters - even if bonds are polar, symmetric molecules (like CO₂) can have zero net dipole moment.
What is a Debye unit?
Debye (D) is a common unit for dipole moments in chemistry. 1 Debye = 3.336 × 10⁻³⁰ C⋅m. It's named after Peter Debye and is convenient for molecular-scale dipole moments.
Can a molecule have zero dipole moment?
Yes! Even if individual bonds are polar, symmetric molecules can have zero net dipole moment. Examples include CO₂ (linear), CH₄ (tetrahedral), and BF₃ (trigonal planar) where bond dipoles cancel out.
How does dipole moment affect intermolecular forces?
Larger dipole moments lead to stronger dipole-dipole interactions between molecules. This increases intermolecular attraction, resulting in higher melting points, boiling points, and viscosity compared to nonpolar molecules of similar size.