Copper(II) oxide Polarity

Reviewed by: Guidechem Scientific Editorial Board

Standards: IUPAC & PubChem Guidelines | Updated: 2026

Is CuO (Copper(II) oxide) Polar or Nonpolar? Molecular Polarity & Structure Analysis

CuO (Copper(II) oxide) is ionic. It is not meaningfully described as "polar" or "nonpolar" at the level of a single molecule: the substance consists of separated ions, so charge separation and hydration — not a molecular dipole — govern how it behaves. The dipole value tabulated for a single ion pair is origin-dependent and is reported below only as a calculated reference number.

2D Lewis Structure of Copper(II) oxide (CuO)

Figure 1: 2D Lewis Structure (CuO)

Polarity Parameters of CuO

CAS Registry Number	1317-38-0
Molecular Formula	CuO
Molecular Weight	79.55 g/mol
Valence Electrons	7
Lewis Structure Guide	View CuO Lewis Structure Guide
Dipole Moment (μ)	Not defined — ionic / multi-component substance; polarity is described through ionicity and solvation rather than a molecular dipole
Dielectric Constant (ε_r)	Not quoted — the Debye estimate would inherit a dipole that this method does not deliver reliably for this class of compound
Snyder Polarity Index (P′)	Not conventionally assigned
XlogP3-AA	Not computed (Crippen parameters do not cover every element here) (computed descriptor)

Note: Snyder P′ is a chromatographic solvent scale developed for conventional liquid solvents; the value shown for the dipole is a single-ion-pair calculation about the centre of mass and is origin-dependent for a charged species; XlogP is a calculated partition descriptor, not a direct measure of solvent polarity.

1. Molecular Polarity Analysis of Copper(II) oxide: Geometry & Dipole Vector

To determine whether Copper(II) oxide (CuO) is polar or nonpolar, the decisive question is whether the bond dipoles of the molecule cancel once its three-dimensional shape is taken into account. Copper(II) oxide is an inorganic compound. As set out in the CuO Lewis Structure Guide, CuO has 1 heavy atom. For Copper (II) oxide (USEPA/OPP Pesticide Code: 042401) ACTIVE products with label matches..

The bond polarities follow from electronegativity. Because the substance separates into ions, the molecule is polar but the magnitude of its dipole is not quoted here, because the species is ionic or carries a net charge, so the dipole depends on the choice of origin and is not a molecular constant.

For formulation and process work, the useful consequences are these: the calculated topological polar surface area is 28.5 Å², 0 hydrogen-bond donors and 0 hydrogen-bond acceptors and the Crippen partition coefficient is not quoted, because the parameter set does not cover every element in the molecule. PubChem’s curated experimental record adds: Copper(II) oxide is Insoluble.

Valence-electron check: Counting valence electrons from the formula: oxygen contributes 1 × 6 = 6 and copper contributes 1 × 2 = 2, giving 6 + 2 = 8 valence electrons.

2. Copper(II) oxide application: For Copper (II) oxide (USEPA/OPP Pesticide Code: 042401) ACTIVE…

PubChem’s use and manufacturing record describes Copper(II) oxide as follows: For Copper (II) oxide (USEPA/OPP Pesticide Code: 042401) ACTIVE products with label matches. These applications are what make the polarity question practical — solvent choice, extraction recovery, cleaning and formulation all turn on how strongly the molecule interacts with polar phases.

The measured physical behaviour recorded for this substance is consistent with that picture. Solubility: Insoluble. Physical Description: Dry Powder;. Density: 6.315 @ 14 °C/4 °C. Melting Point: Decomposes at 1326. These are database values and should be read with the conditions (temperature, purity, pressure) that the source states.

No dilute-gas permittivity is reported here: the Debye estimate would have to inherit a dipole moment that this method does not deliver reliably for this class of compound (the species is ionic or carries a net charge, so the dipole depends on the choice of origin and is not a molecular constant), and for an ionic substance the equation does not apply at all.

The structure carries no strongly polar functional group, so the intermolecular forces are dominated by dispersion rather than by dipole–dipole attraction or hydrogen bonding.

PubChem’s GHS record for this substance lists H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard] and H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]. Those classifications, not the polarity of the molecule, normally determine packaging, labelling, ventilation and transport requirements.

Industrial Sourcing & Compliance Insight: For Copper(II) oxide, the commercially relevant specification is assay, grade, water content and the impurity profile declared on the certificate of analysis, together with the packaging and transport class required for the destination market. Request the certificate of analysis with the enquiry rather than after it: for a substance handled at industrial scale, the declared impurity profile usually decides whether a lot is usable more often than the nominal purity does.

Recommended Analytical Quality-Control Strategy

Identity confirmation: FTIR or Raman against a reference spectrum, supported by GC–MS or LC–MS where the compound is amenable; this is the fastest way to catch a mis-labelled lot.
Assay / purity: GC-FID or GC-MS for volatile material, HPLC with a validated detector for non-volatile or thermally labile material; state the basis (area %, assay on dried substance, or titrimetric) on the certificate of analysis.
Water content: Karl Fischer titration is the default for a substance whose polarity and hydrogen-bonding capacity make it hygroscopic; moisture is the single most common cause of out-of-specification lots.
Inorganic / ionic content: ion chromatography or ICP-OES for the counter-ion and for trace metals; for salts the counter-ion stoichiometry is part of the assay, not an afterthought.
Physical constants: density, refractive index and boiling or melting range against the published values — cheap, fast and often sufficient to reject a lot before any chromatographic work is done.

In short, specify Copper(II) oxide by assay, water content, impurity profile, packaging and transport class, and state the intended application on the enquiry. The polarity analysis above explains behaviour in use; it does not replace a specification.

3. Polarity Comparison: CuO and Related Industrial Fluids

The comparison below places CuO next to structurally related substances from the same catalogue. Dipole moments come from one consistent protocol (GFN2-xTB//MMFF94, gas phase, single conformer) and are quoted only where that protocol has been validated; where it has not, the cell says so instead of giving a number. Permittivities are dilute-gas estimates from the Debye equation, logP values are Crippen calculations, and the solubility column is a qualitative inference from the calculated descriptors rather than a measurement.

Compound	Dipole Moment	Approx. Gas ε_r	log P / XlogP	Water Solubility Behavior	Industrial Sourcing
CuO	non-zero, not quoted	—	—	Insoluble	See supply listing
HO	non-zero, not quoted	—	logP ≈ -0.18	Moderate to high (inferred from logP < 0)	See supply listing
HCs₂O	non-zero, not quoted	—	—	Dissolves by dissociation; ionic hydration dominates	See supply listing
SnO₂	non-zero, not quoted	—	—	Dissolves by dissociation; ionic hydration dominates	See supply listing
HORb₂	non-zero, not quoted	—	—	Dissolves by dissociation; ionic hydration dominates	See supply listing

The spread across this table is the point: composition alone does not set the polarity verdict. CuO sits where it does because of the balance between weak dispersion forces and the asymmetry of its shape, and any of the neighbouring entries can be the better choice once the temperature, the phase and the required polarity window are fixed.

4. Expert R&D Commentary

Expert Chemical Commentary

“CuO is an ionic substance, so the useful question is not "polar or nonpolar" but how the charge is distributed and how strongly the ions are hydrated. No calculated partition coefficient is quoted, because the Crippen parameter set does not cover every element in the molecule. The curated experimental record is consistent: Insoluble.”

5. Regulatory, Safety & Sustainability Trends

Regulatory status is specific to the substance and to the jurisdiction, and it changes. For CAS 1317-38-0 the authoritative public sources are the ECHA registered-substance database for the EU, and the OSHA and NIOSH tables for occupational exposure in the United States.

PubChem’s GHS record for this substance lists H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard] and H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]. These statements are the ones that must appear on the label and in section 2 of the safety data sheet; they, rather than the polarity of the molecule, drive classification, packaging group and transport documentation.

No occupational exposure limit for this substance is quoted in this article, because none was present in the database record used here. Publishing a limit that is not on the record would be worse than publishing none: obtain the applicable value from the OSHA Z-table, the NIOSH pocket guide or the equivalent national instrument before designing the ventilation or monitoring programme.

From a compliance and sustainability standpoint, the polarity of CuO is a means rather than an end. It determines which solvent can replace another, how completely the substance can be recovered from a stream, and how much energy the separation will cost — so it belongs in the process justification, while the hazard classification and the exposure limits belong in the safety case.

6. Guidechem's Procurement Tips: What to Specify for Copper(II) oxide

A purchase enquiry for Copper(II) oxide (CAS 1317-38-0) should state the grade, assay basis, permitted impurity limits, water content, packaging, and the transport and regulatory status required for the destination market. Where the substance is used as a reagent or intermediate, the impurity profile usually matters more than the nominal percentage.

Because polarity governs phase behaviour, it also governs recovery: a polar molecule is easier to strip from a non-polar stream and harder to dry than a non-polar one, and vice versa. Confirm the Guidechem supply listing for current availability and compare lots on the certificate of analysis rather than on the label alone.

Industrial Engineering & Sourcing Specifications

Looking for commercial bulk supplies or technical documentation for Copper(II) oxide (CAS 1317-38-0)?

Browse Verified Suppliers & Request Quotes on Guidechem →

Frequently Asked Questions (FAQs)

Is Copper(II) oxide polar or nonpolar?

Copper(II) oxide is polar. The bond dipoles do not cancel, so the molecule is polar, but no magnitude is quoted because the species is ionic or carries a net charge, so the dipole depends on the choice of origin and is not a molecular constant.

Why is no dipole moment quoted for Copper(II) oxide?

The species is ionic or carries a net charge, so the dipole depends on the choice of origin and is not a molecular constant. Rather than publish a number that would be misleading, the article argues the polarity from structure and symmetry; the literature value can be looked up in the NIST or CRC tables if a number is required.

How does the molecular geometry decide the answer?

Whether the individual bond dipoles cancel depends on how the bonds are arranged in three dimensions. Two identical bonds pointing in opposite directions cancel; the same two bonds at an angle do not.

What is the dielectric constant of Copper(II) oxide?

No permittivity is quoted: the Debye dilute-gas equation does not apply to a charged species.

Does Copper(II) oxide have a Snyder polarity index?

Not in routine tabulations. Snyder P′ was developed for conventional liquid chromatographic solvents, and this substance is outside the scope of that scale. Dipole moment, calculated logP and hydrogen-bond counts are the descriptors used here instead.

How does Copper(II) oxide behave toward water?

The curated database record states: Insoluble. No calculated partition coefficient is quoted, because the Crippen parameter set does not cover every element in the molecule.

What should be checked before buying Copper(II) oxide?

Grade, assay basis, water content, the declared impurity profile, packaging and the transport classification, plus the regulatory status required for the destination market. PubChem’s GHS record for this substance lists H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard] and H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard].

References & Academic Databases

PubChem Compound Summary: Copper(II) oxide, CAS RN 1317-38-0, CID 164827. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov
ECHA Substance Information: Copper(II) oxide, CAS 1317-38-0 — REACH registration status, harmonised classification and regulatory context. European Chemicals Agency.
NIST Chemistry WebBook / CCCBDB: experimental geometry, vibrational data and dipole-moment compilations for Copper(II) oxide. National Institute of Standards and Technology.
CRC Handbook of Chemistry and Physics, 92nd ed. (Haynes, W. M., ed.), CRC Press, 2011 — electronegativity, dielectric constant and dipole-moment tables.
Nelson, R. D.; Lide, D. R.; Maryott, A. A.: Selected Values of Electric Dipole Moments for Molecules in the Gas Phase, NSRDS-NBS 10, National Bureau of Standards, 1967.
Snyder, L. R.: solvent-polarity classification and the P′ scale for liquid chromatographic solvents. The P′ scale is defined only for conventional liquid solvents and is not assigned to substances outside that scope.
Bannwarth, C.; Ehlert, S.; Grimme, S.: GFN2-xTB — an accurate and broadly parametrised self-consistent tight-binding quantum chemical method with multipole electrostatics and density-dependent dispersion contributions. J. Chem. Theory Comput. 2019, 15 (3), 1652–1671.
RDKit / Halgren, T. A.: MMFF94 force field for geometry generation (J. Comput. Chem. 1996, 17, 490–519) and the RDKit cheminformatics toolkit used for the Crippen logP, TPSA and hydrogen-bond descriptors quoted here.

Technical note: Dipole moment, relative permittivity, Snyder P′ and calculated logP are not interchangeable descriptors. For CuO no dipole magnitude is reported: the species is ionic or carries a net charge, so the dipole depends on the choice of origin and is not a molecular constant. The polarity argument therefore rests on symmetry and structure alone; where a number is needed, take it from the NIST Computational Chemistry Comparison and Benchmark Database or the CRC Handbook rather than from a calculation that this benchmark does not support. For this charged species the dipole was computed about the centre of mass; for a net-charged system that quantity depends on the choice of origin and is reported only as a reference number. Procurement and process decisions should rest on application-specific specifications — grade, assay, water content and impurity profile — supported by measured property data, rather than on a single polarity number.

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Copper(II) oxide Polarity