VCE Chemistry Intermolecular Bonds and Polarity

A set of flashcards designed to review key concepts related to intermolecular bonds, polarity, and their effects in chemistry.

Polar Covalent Bond

A bond formed between two covalently bonded atoms with differing electronegativities.

Non-Polar Covalent Bond

A bond formed between two atoms with similar electronegativity.

Polar Bonds

Covalent bonds where bonding electrons are unequally shared between two bonded atoms.

Charge Separation

A phenomenon in polar covalent bonds resulting in a slightly negatively charged atom (δ–) and a slightly positively charged atom (δ+).

Polar Molecules

Molecules that are non-symmetrical with different electronegativities or lone pairs of electrons.

Permanent Dipole

A consistent separation of charge within a polar molecule.

Dipole-Dipole Attractions

Attraction forces between polar molecules.

Hydrogen Bonding

A type of strong dipole-dipole interaction occurring between molecules where hydrogen is bonded to N, O, or F.

Dispersion Forces

The weakest intermolecular forces arising from temporary dipoles in molecules due to electron movement.

Bond Dipole

A vector quantity that represents the polarity of a bond, indicating the direction of electron density.

Covalent Bond

A bond formed by the sharing of electrons between two atoms.

Bond Energy

The amount of energy required to break a bond; stronger bonds have higher bond energies.

Bond Length

The distance between the nuclei of two covalently bonded atoms.

Ionic Bond

A bond formed by the transfer of electrons between atoms, resulting in the attraction of oppositely charged ions.

Molecule

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Non-Polar Molecules

Molecules that are symmetrical and have no unshared pairs of electrons.

Tetrahedral Geometry

A molecular shape where a central atom is surrounded by four other atoms at the corners of a tetrahedron.

Linear Molecule

A molecule in which atoms are arranged in a straight line.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons.

Bonding Electrons

Electrons that are involved in the formation of a chemical bond.

Partial Positive Charge

A slight positive charge that develops on an atom in a polar covalent bond.

Partial Negative Charge

A slight negative charge that develops on an atom in a polar covalent bond.

Lone Pair

A pair of valence electrons that are not involved in bonding.

Molecular Substance

A substance that is made of molecules held together by covalent bonds.

Intermolecular Forces

Forces that occur between molecules, such as dipole-dipole forces and hydrogen bonds.

Electrical Conductivity

A measure of how well a substance can conduct electricity; covalent molecules generally do not conduct electricity.

Boiling Point

The temperature at which a substance transitions from a liquid to a gas, influenced by intermolecular forces.

Melting Point

The temperature at which a substance transitions from a solid to a liquid, influenced by intermolecular forces.

Instataneous Dipole

A momentary distribution of charge in a molecule due to the movement of electrons.

Greater Electronegativity

The property of an atom that indicates a greater ability to attract electrons.

Valence Electrons

Electrons that are found in the outermost shell of an atom and are involved in forming bonds.

Polar Bond Example

The bond between hydrogen and fluorine in hydrogen fluoride (HF).

Non-Polar Bond Example

The bond between two hydrogen atoms in H2.

Ionic Bond Example

The bond between sodium and chlorine in sodium chloride (NaCl).

Polar Molecule Example

Water (H2O), which has a bent shape and polar bonds.

Non-Polar Molecule Example

Methane (CH4), which has a symmetrical tetrahedral shape.

Symmetrical Molecules

Molecules where all sides are identical, leading to cancellation of dipoles.

Dipole Strength Factor

The strength of a dipole depends on the electronegativity difference between the bonded atoms.

Molecular Shape Influence

The shape of a molecule affects how closely they can approach each other, influencing intermolecular attraction.

Electronegativity Table

A comparative chart displaying electronegativity values of different elements.

Van der Waals Forces

A general term for intermolecular forces, including dispersion forces.

High Boiling Point Implication

A substance's high boiling point indicates strong intermolecular attractions, often due to hydrogen bonding.

Hydrogen Bonding Significance

Hydrogen bonding significantly affects the properties of substances like water.

Lone Pair Effect

Lone pairs can alter the shape and polarity of molecules.

Chemical Polarity

The distribution of electrical charge over the atoms joined by the bond.

Molecular Interaction Types

Different interactions such as dipole-dipole, hydrogen bonding, and dispersion forces exist between molecules.

Strongest Intermolecular Force

Hydrogen bonding is typically the strongest among intermolecular forces.

Covalent Network Substances

Substances where atoms are bonded covalently in a continuous network, significantly affecting melting and boiling points.