Nmat Chemistry

Matter

Anything that has mass and takes up space

Mass

The amount of matter in an object

Volume

The amount of space an object takes up

Phases of Matter

Solid, Liquid, Gas

Solid

Compact
Incompressible
Definite shape and volume
Usually has low temperature

Liquid

Compact to tightly spaced
Indefinite shaped but definite volume
Incompressible
Usually has low to high temperature

Gas

Spaced apart
Indefinite shape and volume
Compressible
Usually have high temperature

Phase Changes

Freezing/Solidification
Melting/Liquifaction
Condensation
Evaporation
Sublimation
Deposition

Freezing/Solidification

Liquid to solid

Melting/Liquifaction

Solid to liquid

Condensation

Gas to liquid

Evaporation

Liquid to gas

Sublimation

Solid to gas

Deposition

Gas to solid

Density

Mass per unit volume

Specific gravity

Ratio of DENSITY of sample and density of reference substance (usually H2O)

Used to determine whether a sample would float on another substance

Apparent Specific Gravity

Ratio between WEIGHTS of equal volumes of a sample and water

True Specific Gravity

Ration between the weights IN A VACUUM of equal volumes of a sample and water

Intensive Properties

Do not depend on the amount of matter present

Boiling, Freezing, Melting Points
Density
Buoyancy (ability to float)
Ductility (wire ability)
Malleability (sheet ability)
Elasticity (returning to original shape)
Viscosity (ability to resist flow

Extensive Properties

Depend on the amount of matter that is present

Mass
Volume
Energy (energy stored in object)
Entropy (measure of disorder)
Electrical charge (total charge of particles)

Types of Matter

Pure Substances
•Elements
•Compounds
Mixtures

Pure substances

Made of only one kind of substance

Elements
Compounds

Elements

Made of only 1 kind of atom

Nonmetals
Metals
Metalloids

Nonmetals

Number of valence electrons is close to completing the octet rule
Accepts electrons during ionic bonding
Forms ANIONS when ionized

Brittle solids
Poor conductors of heat and electricity
High electronegativity and ionization energy

Metals

Number of valence electrons is small
Donates electrons during ionic bonding
Forms CATIONS when ionized

Usually solid, malleable, ductile and can be plastically deformed
Highly conductive for heat and electricity (with the exception of a few elements)
Low electronegativity and ionization energy
High melting point and density

Metalloids

Properties are in-between metals and non-metals
Reactivity depends on the elements to be reacted with

Compounds

Made up of atoms of two or more elements in fixed proportions

Ionic
Covalent
Metallic

Ionic compound

Components are a pair of anion group and cation group
Electrons are transferred from cation to anion

Covalent compound

Components are BOTH anion groups
Electrons shared within the bond

Metallic Bonding

Components are both metals
Electrons are stored in a "sea of electrons"

Mixtures

A combination of two or more substances that are not chemically combined.

Homogenous
Heterogenous

Homogenous Mixture

Only 1 phase is discernable
Commonly called "solutions"

Concentration

Measure of the amount of solute in a given amount of solvent or solution

Solute

A substance that is dissolved in a solution.

Solvent

A liquid substance capable of dissolving other substances

Solubility

The maximum amount of solute that can dissolve in a given amount of solvent under specific conditions

Solubility Rule

All nitrates are soluble NO₃
All chlorides are soluble except AgCl, Hg₂Cl, and PbCl₂
Most sulfates are soluble; except BaSO₄ PbSO₄ and SrSO₄
All carbonates are insoluble except NH₄+ and those of group 1
All hydroxides are insoluble except those in group 1, Ba(OH)₂ Sr(OH)₂ and Ca(OH)₂
All sulfides are insoluble except those of Group 1, 2 and NH₄

Heterogenous Mixture

Mixtures with 2 or more distinct phases that are discernable

Suspensions
Colloids

Suspensions

Suspended particles are too large and too heavy to be carried by the motion of the particles in which they are suspended, causing them to SETTLE after some time

Colloids

Suspended particles are small and light enough to be carried by the movement of the particles in which they are suspended in

Types of colloids

Solid sol
Sol
Solid aerosol
Emulsion
Gel
Aerosol
Solid foam
Foam

Solid sol

Solid in solid
Ex. Colored glass, ruby, opal

Sol

Solid in liquid
Ex. Paint, blood

Solid aerosol

Solid in gas
Ex. Smoke, ice clouds, air particulates

Emulsion

Liquid in liquid
Egg, milk, hand cream

Gel

Liquid in solid
Ex. Agar, gelatin

Aerosol

Liquid in Gas
Ex. Fog, cloud, hair spray

Solid foam

Gas in solid
Styrofoam, aerogel, pumice

Foam

Gas in liquid
Ex. Shaving cream, Whipping cream

Atomic Theory of Matter

1. All matter is made up of atoms.
2. Atoms of the same element are identical.
3. Atoms can combine to produce other substances.
4. Atoms combine in specific proportion to a specific substance.

Components of an Atom

Protons, Neutrons, Electrons

Proton, p

Mass: 1 amu
Charge: +1
Found in nucleus

Neutron, n

Mass: 1 amu
Charge: 0
Found in nucleus

Electron, e

Mass: negligible
Charge: -1
Moves around the nucleus

Radioactivity

Breaking down of nucleus with the emission of α, β, and γ rays.
Results in the formation of a new element

Properties of an Atom

Atomic Number, Mass number, Charge

Atomic Number (Z)

the number of protons in the nucleus of an atom

Mass Number (A)

the sum of the number of protons and neutrons in the nucelus of an atom

Charge (Q)

Equal to the difference of number of protons and number of electrons

Isotopes

Atoms of the same element that have different numbers of neutrons resulting in a different mass number

Percent Natural Abundance

Relative abundance of a certain isotope compared to all the isotopes of the same element

Relative Atomic Mass

Weighted average of the mass numbers of the isotopes with regard for the relative amount of 2 isotopes

Periodic Table of Elements

Arrangement of chemical elements in order of increasing atomic number.

Groups: vertical columns, have similar properties and similar outer electron arrangements
Periods: horizontal rows

Group 1A

Alkali Metals
Charge: +1
Soft Metallic Solids
Shiny and lustrous
Reacts vigorously with water to produce hydroxides

Group 2A

Alkaline Earth Metals
Charge: +2
Harder than 1A metals
Shiny, lustrous
Oxidizes easily

Group 3A

Boron Group/ Earth Metals
Charge: 3+

Group 4A

Carbon Group/ Tetrels
Charge: either 4+ or 2+

Group 5A

Nitrogen Group/ Pnictogens
Charge: either 5+ or 3+

Group 6A

Oxygen Group/ Chalcogens
Charge: -2

Group 7A

Halogens
Charge: -1
Reactive non-metals

Group 8A

Noble Gases
Already have eight electrons
Unreactive under ordinary circumstances
Have little tendency to either gain or lose electrons
Do not readily form ionic or molecular compounds
Found usually as monoatomic gasses
Colorless and odorless

Group B

Transition metals
Lanthanide Series
Actinide Series

Transition Metals

Hard and metallic
Shiny and lustrous
Dense and have high melting points
Usually high oxidation states
Have partially filled d subshl
Comprise groups 3 to 12

Lanthanide Series

Elements 58 to 71
Often called "f-elements" because they have valence in the f shell

Actinide Series

Elements 89 to 103
Also called "f-elements"
Only Thorium (Th) and Uranium (U) occur naturally with significant abundance
All radioactive

Electronegativity

Tendency of an atom to attract a bonding pair of electrons
Increases from left to right along a period
Decreases from top to bottom along a group

Factors that affect electronegativity
Atomic Radius (inversely proportional)
Nuclear Charge
Screening by inner orbitals

Ionization energy

Energy required to remove an electron from an atom
Increases from left to right along a period
Decreases from top to bottom along group

Atomic size/Radius

The farthest extent of the presence of electrons
Decreases from left to right along a period
Increases from top to bottom along a group

Electron Affinity

The energy change that occurs when an electron is acquired by a neutral atom
Positive when energy is released
Negative when energy is absorbed
Generally increases from left to right along a period
Generally decreases from top to bottom along a group
Unit: kJ mol-¹

Compounds

Formed when two or more elements combine chemically

Chemical bonding

The combining of atoms to form molecules or ionic compounds

Ionic bonding

a.k.a. Electrovalent Bonding
Metals lose electrons to form positive ions
Non metals gain electrons
Form crystals with high melting and boiling points
Poor conductors when solid, but good conductors when dissolved in water.

Lattice

Packing together of ions in a repeating array

Lattice energy

The energy required to separate one mole of the ions of an ionic compound

Covalent Bonding

A bond formed when atoms share one or more pairs of electrons in a molecular orbital

Substances containing covalent bonding:
Low melting and boiling points
Tend to be soft, relatively flexible and more flammable
Solubility in water is low, dissolve in non-polar or organic liquids but do not conduct electricity

Coordinate Bonding

a.k.a. Dative Covalency
A pair of electrons is shared between two atoms BUT one atom supplies both electrons while the other supplies none

Hydrogen Bonding

The chemical bonding of a hydrogen atom with another electronegative atom (usually fluorine, oxygen or nitrogen)
No effect on chemical properties, but increased boiling point and viscosity.

Dipole-dipole Attraction

Permanent forces of attraction in polar molecules contain permanent dipoles

Van der Waals forces

Forces of attraction induced between particles that approach one another to induce a slight charge due to slight movement of electrons

Metallic bonding

Atoms in a metal are closely packed together in a metallic lattice and bonding within lattice is very strong
Have moderately high melting points
Malleable and ductile
Good conductors of heat and electricity

Empirical formula

Shows the simplest ratio of the amounts of atoms of each component elements

Molecular formula

Shows the types and numbers of atoms combined in a single molecule of a molecular compound

Structural formula

Represents the covalent bonds by dashes and shows the arrangement of covalently bonded atoms

Mole

Relative atomic mass in grams
1 mole \= 6.022×10²³

Ideal Gas Concept

All interactions between the molecules are only through collisions that are assumed to be completely elastic

Gases have mass but no volume
Exists in Standard Temperature and Pressure of 0⁰ and 1 atm
At STP, 1 mole of gas occupies 22.4 L

Gas laws

Simple mathematical relationships between the volume, temperature, pressure, and quantity of a gas

Unit if temperature: Kelvin

Boyle's Law, Charles' Law, Gay Lussac's Law, Avogadro's Law, Combined Gas Law, Dalton's Law of Partial Pressures

Boyle's Law

A particular amount of gas @ a constant T increases in volume when pressure is decreased.
⬆️ P \= ⬇️ V @ constant T

Charles' Law

The volume of a fixed mass of gas at constant pressure is directly proportional to absolute temperature

⬆️T \= ⬆️V @constant P

Gay-Lussac's Law

A particular amount of gas at constant volume increases in temperature when the pressure is increased
⬆️T \= ⬆️P @constant V

Avogadro's Law

A gas under constant pressure and temperature increases in volume when the amount of particles is increased
⬆️Volume \= ⬆️ Mole