GENERAL CHEMISTRY

Kinetic Molecular Model

Theory explaining the state of matter based on tiny particles in constant motion.

Kinetic Energy

Energy of motion; energy actively used for movement by moving particles.

Molecule

A group of two or more atoms held together by chemical bonds.

Solid

Rigid state of matter with fixed shape and volume; closely packed particles.

Malleability

Ability of a material to be hammered into thin sheets without breaking.

Ductility

Ability of a material to be stretched into thin wires without breaking.

Liquid

State of matter that is not rigid, has fixed volume, and takes the shape of its container.

Gas

State of matter that moves freely, has low density, and weak intermolecular forces.

Melting

Phase change from solid to liquid.

Ionization

Phase change from gas to plasma.

Condensation

Phase change from gas to liquid.

Evaporation

Phase change from liquid to gas.

Sublimation

Phase change from solid to gas.

Recombination

Phase change from plasma to gas.

Freezing

Phase change from liquid to solid.

Deposition

Phase change from gas to solid.

Temperature Scales

Kelvin, Celsius, Rankine, Fahrenheit.

the kinetic energy also increases

If the absolute temperature scale increases;

Absolute Zero

The coldest possible temperature where particles are stationary (0 Kelvin or -273.15 ℃ or -460 ℉).

Heat Flow

Movement of heat depends on attractive forces in a substance.

Volatility

Ease of evaporation of a liquid or substance.

Intermolecular Forces

Forces that hold molecules together or are in between molecules; weaker than intramolecular forces.

1. Van der Waals- London Dispersion Force, Dipole-dipole Interaction: Hydrogen Bonding

2. Ion-Dipole Interaction

Types of Intermolecular Forces

Johaness Diderik van der Waals (1837-1923)

van der waals forces was named after him; a Dutch physicist

London Dispersion Force

happens when one molecule with a temporary dipole exerts a weak attractive force on another molecule; occurs in all types of molecules

polarization

Dispersion force is caused by ____, or the distortion of electron

polarizability

Number of electrons affects the ____ of the atom

London Dispersion Force

weakest among intermolecular forces

London Dispersion Force

responsible for condensation and solidification of these molecules

London Dispersion Force

temporary dipole; the result of formation of a partially positive and negative atom

Dipole-dipole Interaction

occurs between partially positive (+) and partially negative (+) ends;

Dipole-dipole Interaction

interaction is observed in polar covalent molecules such as amino acids, wherein the electrons are shared both by oxygen atom;

Dipole-dipole Interaction

effective over short distance only as it is still weak; increase in temperature diminishes the strength of this interaction

Hydrogen Bonding

a special kind of dipole-dipole interaction formed when hydrogen bonds with fluorine, oxygen or nitrogen;

2x^-10 meters

distance needed for hydrogen bonding

Hydrogen Bonding

partially positive end of the hydrogen atom is attracted to the partially negative end of fluorine, oxygen, or nitrogen;

Hydrogen Bonding

weaker than ionic or covalent bonding but is the strongest intermolecular force of attraction;

Hydrogen Bonding

reason for the high melting and boiling point of water, ammonia, and alcohol such as methanol

Ion-dipole Interaction

arises from the interaction between an ion and a polar molecule; responsible for formation of cations in a solution

15 kj/mol for 500 parts/mil distance

distance for ion-dipole interaction

Anion

If molecule is an ____, it will be attracted to the partially positive end of the polar molecule

Cation

If molecule is a ____, it will be attracted to the partially negative end of the polar molecule

Cations

formed from ionic solid such as calcium dichloride (CaC12)

Intramolecular Forces

responsible for interaction within a molecule; generally stronger; forces that hold atoms within a single molecule

Ionic, Covalent

Types of Intramolecular Forces

Ionic Bonding

Transfer of electrons between atoms, forming ionic compounds.

Covalent Bonding

Sharing of electrons between atoms, forming covalent compounds.

Hydrogen Bonding & Dispersion Force

H2O (oxygen disperses)

Dispersion Force

CH4 (high dispersion)

Dipole-dipole interaction

HCl (high attraction)

Ion-induced dipole interaction

Mg (positive interaction)

Dispersion force

C2H2

ion-induced dipole interaction

K^+

Surface Tension

tension of the surface film of a liquid caused by the attraction of the particle on the surface layer by the bulk of the liquid; tends to minimize the surface area

Surface Tension

amount of energy needed to conquer forces between molecules of the liquid’s surface and increase its surface area

Surface Tension

Spherical shape encloses the greatest volume of matter with the least amount of surface area

Cohesion

Attraction between liquid and liquid.

Adhesion

Attraction between solid and liquid.

Viscosity

The ____ of a substance depends on the intermolecular force that holds its molecules together

the greater the resistance to flow

the more viscous a liquid substance is

Vapor Pressure

created by faster molecules that break away from the liquid or solid and enter the gas phase

increase

It is expected that vapor pressure will ___ with the temperature;

volatile

substances with high vapor pressure are said to be ____

Molar Heat of Vaporization

Energy required to vaporize 1 mole of a liquid at a given temperature.

Structure of Water

Exhibits hydrogen bonding, leading to unique density properties.

Hydrogen bonds

Water’s _____make solid ice less dense than liquid water and allow ice to float.

Tetrahedral

Water molecules form hydrogen bonds, giving ____ structuring held by four neighboring molecules

tetrahedral

means four faced

100 degrees C

boiling point of water

thermal expansion

Above 4℃, ____ will occur causing the density of water to increase

more, less

Even with the same mass, cold water is ___ dense while hot water is ___ dense.

Types and Properties of Solids

classified into arrangement of particles

Crystalline & Amorphous

Types of Solids

Crystalline Solids

symmetrical structure, electrostatic attraction (e.g. crystal rocks, salt (NaCl), potassium chloride (KCl), and potassium bromide (KBr)

• Ionic

• Covalent

• Molecular

• Metallic

Types of Crystalline

Ionic crystals

type of crystalline solids that are ionic compounds composed of cations and anions

Covalent crystals

type of crystalline solids that are held together by covalent bonds

Molecular Crystals

type of crystalline solids that are made of molecules whose attractive forces include; dipole-dipole, dispersion and hydrogen bonding

Metallic crystals

in this type of crystalline solids, the principal constituent particles are atoms of the same metal

metals

have one to four electrons thus empty orbitals in the last energy level

Amorphous Solids

Non-crystalline; do not have a regular structure and have a more random arrangement of particles (e.g. plastics, polymer, glass)

phase changes

conversions from one state of matter to another by adding or removing heat

40.79 kj/mol

Liquid-Vapor Equilibrium (IF LIQUID TO GAS)

-40.79 kj/mol

Liquid-Vapor Equilibrium (IF GAS TO LIQUID)

6.01 kj/mol

Solid-Liquid Equilibrium (IF SOLID TO LIQUID); melting

-6.01 kj/mol

Solid-Liquid Equilibrium (IF LIQUID TO SOLID); freezing

4.18 j/g c

specific heat capacity of LIQUID WATER

1.99 j/ g c

specific heat capacity of ICE

2.09 j/ g c

specific heat capacity of STEAM

triple point

point at which three curves intersect in the phase diagram of water

triple point

point that gives the pressure and temperature at which all three states are in equilibrium

5.2 atm & 57 degree celcius

triple point of carbon dioxide (CO2)

liquid, not stable

Below 5.2 atm (including 1 atm or atmospheric pressure at sea level), ___ phase is ____

1 atm & -78.5 degree celcius

At ____, the solid CO2 (dry ice) will sublime or undergo sublimation

solution

homogeneous mixture of two or more substances

homogeneous

Solution is categorized as a ____ mixture because its components are indistinguishable from one another

solute, solvent

components of solution

solute

component of solution that is lesser in quantity

solvent

component of solution that is larger in quantity

Solid type of solution

solid in solid, liquid in solid, gas in solid