Intermolecular-Force.pptx

INTERMOLE CULAR FORCE FORCE May be defined as push or pull upon object resulting from the object’s interaction with another object. FOUR FUNDAMENTAL FORCES OF NATURE Strong Nuclear Force This force is the one that holds protons and neutrons in the nucleus of an atom....

INTERMOLE CULAR FORCE FORCE May be defined as push or pull upon object resulting from the object’s interaction with another object. FOUR FUNDAMENTAL FORCES OF NATURE Strong Nuclear Force This force is the one that holds protons and neutrons in the nucleus of an atom. Hiroshima and Nagasaki Bombing, 1945 FOUR FUNDAMENTAL FORCES OF NATURE Strong Nuclear Force This force is the one that holds protons and neutrons in the nucleus of an atom. Hiroshima and Nagasaki Bombing, 1945 FOUR FUNDAMENTAL FORCES OF NATURE Electromagnetic Force This force binds electrons to the atomic nucleus and it basically deals with attractive and repulsive interaction of electrical Friction charges. FOUR FUNDAMENTAL FORCES OF NATURE Weak Nuclear Force This force is involved in the important processes such as radioactive decay or the breaking down of heavy atomic particles which eventually forms new elements in stars Supernova and supernova explosion. FOUR FUNDAMENTAL FORCES OF NATURE Gravitational Force This force causes object to be pulled towards the earth. Gravity Intermolecular Force This is the attractive force or bond between molecules which is responsible for keeping matter in its solid or in its liquid phase. DIPOLE a pair of equal and oppositely charged or magnetized poles separated by a distance. ION any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions are called anions.  FOUR TYPES OF INTERMOLECULAR FORCES OF ATTRACTION (IMFA) London Dispersion Forces This force is present in all molecules whether polar or non-polar. This IMFA was named after the German- American physicist Fritz London who proposed the origin of this intermolecular attractions.  FOUR TYPES OF INTERMOLECULAR FORCES OF ATTRACTION (IMFA) Ion-Dipole Forces This results from the electrostatic attraction between an ion and a molecule containing a dipole. The strength of this force increases as the charge of the ion increases.  FOUR TYPES OF INTERMOLECULAR FORCES OF ATTRACTION (IMFA) Dipole-Dipole Forces This results from the electrical interactions among dipoles on neighboring. This is only present in polar molecules.  FOUR TYPES OF INTERMOLECULAR FORCES OF ATTRACTION (IMFA) Hydrogen Bonding This special type of dipole-dipole interaction occurs when hydrogen is bonded to (its best friends) Fluorine, Oxygen, and Nitrogen F, O, N, are three of the most electronegative elements Properties of Matter Influenced by the Intermolecular Forces Solubility Refers to the ability of a substance to dissolve in a given amount of solvent at a specified temperature. The solute is the substance that is being dissolved, while the solvent is the dissolving medium Solubility If two liquids dissolve or mix together, they are called miscible liquids. If two liquids do not dissolve or mix together, they are called immiscible liquids. Solubility Substances or molecules that form interactions with water are also described as hydrophilic. Dipole-dipole forces and hydrogen bonding are the primary IMFA in hydrophilic substances. Solubility Substances or molecules that repel water are described as hydrophobic. London dispersion forces are the primary IMFA in these substances. Melting Point The temperature at which a substance changes from solid to liquid. Substances with stronger IMFA have higher melting points Boiling Point The temperature at which a substance changes from liquid to gas. Substances with stronger IMFA have higher boiling points compared to those Surface Tension The force that causes molecules on the surfaces of the liquid to be pushed together and form a layer. Surface Tension Cohesive forces are attractive forces that exist between molecules of the same kind while adhesive forces are attractive forces that exist between the molecules of different types. Surface Tension Molecules with stronger intermolecular forces will exert greater cohesive forces and acquire less surface area than those with weaker IMFA. This means… liquids with strong IMFA have high surface tensions and liquids with weaker IMFA have low surface tension. Viscosity The measure of a fluid’s resistance to flow. It is often referred to as the thickness of a fluid. Molecules with stronger intermolecular forces have higher viscosity compared to those with weaker Vapor Pressure The pressure exerted by vapor in equilibrium with its liquid phase in a closed system. Substances with stronger IMFA have lower vapor pressure compared to those with weaker IMFA.  Strength of intermolecular forces compounds with compounds compounds compounds London dispersion with dipole- with ion- with forces dipole forces dipole forces hydrogen bonding