Grade 12 - Gen Chem 2 - 1st Qtr

Direct Relationship

Relationship between temperature and solubility for solid.

Inverse Relationship

Relationship between temperature and solubility for gas.

Direct Relationship

Relationship between pressure and gas solubility.

Vapor Pressure Lowering

Dissolving a non-volatile solute lowers the vapor pressure by slowing the escape of solvent molecules.

Boiling Point Elevation

Lower vapor pressure means the solution heeds a higher temperature to reach atmospheric pressure and boil.

Freezing Point Depression

Solute disrupts the orderly freezing of solvent molecules, so the solution freezes at a lower temperature.

Osmotic Pressure

This is the external pressure needed to stop the solvent from entering the solution via osmosis. It increases with higher solute concentration.

Electrolytes

Ionize in solution, allowing it to conduct electricity due to free-moving ions.

Nonelectrolytes

Do not ionize, so they do not conduct electricity.

Activation Energy

The minimum energy needed for a reaction.

Collision Frequency

Number of collisions per second per unit volume of the reacting mixture.

Role of Activation Energy

Only molecules with energy _> Ea can potentially react.

Arrhenius

Coined the Role of Activation Energy

Temperature

Higher temperatures increase the average kinetic energy of molecules, making them move faster and collide more effectively, speeding up the reaction.

Concentration

Increased concentration of reactants leads to more frequent collisions, increasing reaction rate.

Surface Area & Physical State

Reactions happen faster when reactants are in the same phase. For solids, only surface molecules react, so increasing surface area speeds up reactions.

Nature of Reactants

Different substances have unique structures (ions, atoms, molecules), which affect how easily they react with others.

Catalysts

Speeds up reactions by offering an alternative reaction pathway, without being consumed in the process.

Rate Law

Shows how the rate depends on the concentration of reactants.

Energy

The ability to do work or transfer heat.

Kinetic Energy

Energy of motion.

Potential Energy

Energy due to position relative to a reference point.

Chemical Energy

Stored in the bonds of chemical compounds due to electrical and magnetic attractions.

Thermal Energy

Caused by movement of atoms or molecules.

Nuclear Energy

Produced from atomic reactions.

Releases heat and light.

Fusion

Nuclei combine, releasing energy.

Fission

Nucleus splits into smaller nuclei, also releasing energy.

Radiation

Energy transmitted as rays, waves, or particles.

Includes visible light, infrared, and ultraviolet radiation.

Exothermic Reactions

Release heat/light.

Products have less enthalpy than reactants.

Endothermic Reactions

Absorb heat/light.

Products have more enthalpy than reactants.

Hess’s Law

Total enthalpy change of a reaction is the sum of the enthalpies of its individual steps.

Based on the law of conservation of energy.

Solution

A homogeneous mixture of two or more substances, typically consisting of a solute dissolved in a solvent.

Solute

The substance that is dissolved in a solution, typically present in a lesser quantity than the solvent.

Solvent

The substance in which a solute is dissolved to form a solution, usually present in a greater quantity.

Aqueous

Water is the solvent.

Non-Aqueous

Referring to a solution where the solvent is not water, often using organic solvents instead.

Unsaturated

A solution that contains less than the maximum amount of solute that is capable of being dissolved.

Saturated

A solution that contains the maximum amount of solute that is capable of being dissolved.

Supersaturated

A solution in which the solute present is in an excess amount and is dissolved forcefully in the solvent by raising the temperature.

Concentrated

This solution has a relatively large amount of solute dissolved in a given amount of solvent.

Dilute

This solution has a relatively small amount of solute dissolved in a given amount of solvent.

Isotonic

The two solutions (in the cell and in the beaker) have the same concentration of solute in it.

Hypertonic

The solution in the beaker has a higher concentration of solute compared to the solution in the cell. This causes the water from the cell to come out into the solution in the beaker which results to shrinking of the cell.

Hypotonic

The solution in the beaker has a lower concentration of solute compared to the solution in the cell. This causes the water from the beaker solution to move into the cell which makes the cell to swell up or burst.

Stoichiometry

Deals with the quantitative relationships of reactant and products using the law of conservation of mass.

Balanced Equations

Essential for calculating how much product forms or how much reactant is needed.

Liquids

An intermediate phase between solids and gases, with particles that are not fixed in position, allowing them to take the shape of their container.

Have limited compressibility due to the small spaces between particles

Viscosity

A liquid’s resistance to flow.

Capillary Action

The ability of a liquid to flow through narrow spaces due to adhesive and cohesive forces, sometimes against gravity.

Cohesive Force

Attraction between like molecules.

Adhesive Force

Attraction between unlike molecules.

Surface Tension

Cohesive forces at the surface creating a film like effect.

Heating Curves

Graphs temperature versus time as a substance is heated.

Plateaus

Flat segments in the curve represent phase changes where temperature remains constant.

Melting

Solid to Liquid

Boiling

Liquid to Gas

Cooling Curves

Shows temperature changes as a substance cools, with plateaus at phase changes.

Solid

Definite shape and volume.

Liquid

Definite volume, no definite shape

Gas

No definite shape or volume

Phase Diagrams

Display the physical state of a substance as a function of temperature and pressure.

Kinetic Molecular Theory

It explains how atoms and molecules behave in different states of matter and how they interact with energy (such as temperature) and other variables like pressure and volume.

Solids

Lowest Energy

Gases

Highest Energy

Phase Change

Happens when there is a change in energy.

Matter

Is made of particles in constant motion.

Intermolecular Forces

Exist between particles and become stronger as particles get closer.

Intermolecular Forces of Attraction

These are temporary attractive forces between molecules, different from ionic and covalent bonds. They do not involve electron sharing, and they are generally weaker and short-lived.

Ion-Dipole Interaction

Between a charged ion and a polar molecule.

Dipole-Dipole Interaction

Between two dipoles (molecules with a positive and a negative end).

Results in a polar molecule.

Hydrogen Bonding

A special dipole-dipole interaction.

Between hydrogen and oxygen, nitrogen, or fluorine.

London Dispersion Forces

Weakest type of IMFA

Non-polar

Occur in all molecules, even nonpolar ones.

Ionic Bond

Transfer of electrons.

Covalent Bond

Sharing of electrons.

Non-Polar

Shared equally

Polar

Shared unequally