Chemistry Regents Review

Daltons Theory

Hard Sphere and Smallest Indivisible Particles

JJ Thompson Theory

Used a cathode ray tube to discover the electron

Rutherford’s Gold Foil Experiment

• An atom is made up of Mostly empty space

• The nucleus is small, dense, and positively charged

Wave mechanical model (electron cloud theory)

An atom is located within an orbital with in the Electron cloud

Proton

• 1 atomic mass unit

• +1 Charge in the nucleus

• Atomic Number

Atomic number

• The periodic table is organized through atomic number

Neutron

• 1 amu or u, 0 charge, located inside nucleus

• Atomic mass - atomic number= neutron

Electron-

• 0 amu or u or 1/1836 of the mass of a proton, -1 charge, located outside nucleus

Atomic Number/ Nuclear charge-

number of protons in the nucleus, found on the periodic table

Ex:

Atomic Mass/Mass#/Nucleons-

mass of an elements naturally occurring isotopes. protons + neutrons make up an elements mass.

1. Isotope-

is an element that contains the same atomic # different atomic mass, different # of neutrons.

Isotopic Average Mass-

The acceptod values for the atomic mass and percent natural abundance of each naturally occurring isotope of silicon are given in the data table below.

Ground state clectron configuration-

When an electron is at the lowest energy level, Electron figuration is found on the periodic table

Excited state electron configuration

When an electron absorbs energy and jumps up to a higher energy level

Bright light spectrum

When an Electron and side state(emits) Energy and falls back to the ground state in the form of light

Principal energy level (shell)

Fr: 2-8-18-32-18-8-1

You can use FR to compare how many occupied principal levels there are and how many filled principal levels there are

Distance from nucleus, affects energy

• The closer you are to the nucleus of an atom, the less energy and electron has

• The further way you are from the nucleus, the more energy and electron has

think of rubber band

Valence electrons

Outermost electrons within the electron configuration

Ex: Se=2-8-18-6

All Atoms

All atoms are electrically neutral

Equal protons and equal electrons

ZERO Charge

Ions

(+) or (-) charged particles

(+) charge = lose electrons

(-) charge = gain electrons

Atomic Radius and Ionic Radius

Radius- measures half the diameter of the atom

Periodic trend

• The periodic table is arranged according to atomic number, not atomic mass

• The number of protons tells you the atomic number of an element element

Period (Principal energy Level, Shells)

Horizontal rose, moving from left to right across the periodic table

Groups

Vertical columns, 18 in total, elements in groups have similar characteristics because they have the same number of valence electrons

Group 1 (alkali) Metals

1 word for group 1

Group 2 (Alkaline earth) metal

Two words for group 2

Transition metals (Group 3-12)

Halogens

Diatomic elements:elements that naturally exist as molecules composed of two atoms of the same element bonded together

Group 16 (Noble Gases)

Metallic Character

• Malleable to bend

• Make make two wire

• Good conductor of heat and electricity

• Luster-shine

• Loses electron when it bonds

• HMP,LE,LI

Characteristics of nonmetals

• Dull, poor conductors of heat and electricity

• brittle in the solid state ex: glass

• negative charge gained electron

• all three phases of matter are LMP, HI, HE

Ionization energy

• Amount of energy needed to remove an electron

• Group 18 elements have the highest ionization energy because they already have a filled electron shell, and Noble gases, don’t want to lose their valences electron

Electronegativity

• Attraction for electrons

• Chlorine is the most electronegative

• Group 18 elements have no electronegativity number because they are noble gases

• Group 1 elements have the low electronegativity value because they have one valence electron

• Ex: FR=0.2 weakest F=4.0 strongest

Drawing compounds

Drawing compound look at table E First to see if it’s there, if not, then it’s an element on the periodic table. Reduce the lowest terms before crisis crossing down. When an element crosses down only place a parentheses when a compound is present. The Roman numeral represents the positive charge, Only transition metals have Roman numerals

Naming compound

When naming compounds be aware that transition metals produce Roman numerals if a substance is not on table E then it ends ide.

Determining which group an element belongs

By looking at the number of atoms an element has, we can determine both the charge and the group number by reversing the number of atoms up Left side elements has a positive charge and right side elements have a negative

BARF

broken/Absorbed

Release/Form

Ionic bonds

• Bond between a metal and a nonmetal to form a stable octet of electrons

• Transfer of electrons to form ionic bonds

Polar

1.7⬆ Ionic

1.6-1 polar

0 nonpolar

characteristics of ionic solids(Salt)

• Hard

• High melting point

• Crystalline structure

• Poor conductor of as solid, good conductor as a liquid or aqueous because a free moving ions

Covalent bonds

Sharing of electrons between nonmetals to form a stable octet of valence electrons

Nonpolar covalent bond

Equal sharing of electrons between two of the same(Diatomic) Nonmetals

Polar covalent bond

Unequal sharing of electrons between two Different nonmetals

Characteristics of molecule solids(People)

• Soft

• Low melting point

• Poor conductor of electric electricity

Both ionic and covalent bonds

Compounds that both contain ionic and covalent bonds must fit a criteria with at least three or more elements

Is usually combined with a table E element

Ex: NaCIO3 = Na, CI, O

Metallic bonds

A metal by itself represents a metallic bond, Positive ions immerse in a sea of mobile electrons

Hydrogen bonding

When hydrogen bonds with fluorine, oxygen, or nitrogen (FON)

These compounds have unusually high melting points and high boiling points

Van Der Waals Force of Attraction (London Dispersion Forces)

Attraction increases as distance decreases, and mass increases

intermolecular forces

The attractive forces between molecules. Higher the melting point or boiling point the stronger, the intermolecular forces of attraction, the lower and weaker the intermolecular forces of attraction.

my answer is either strong or weak.(high melting/boiling point equals strong=low melting/boiling points equals weak’

SLG

molecule ion attraction

Ionic compounds (salt) Bonds with a water molecule

Molecule Types

Symmetrical/Nonpolar

Asymmetrical/polar

Balancing equations

• When two elements are on the same side balance last

• Get the items to equal up

Formula (Molecular Mass)

Finding the mass of each element and multiplying them by the number of atoms that determine the gram formula mass

% Composition

Mass of part/mass of whole x 10

Percent composition of hydrate

Hydrate-A salt that contains a loosely bonded water molecule, Think of CuSo4 o 5H2O (Blue salt)

Big # - Small #/Big # x 100

Anhydrous-when water evaporates leaving just salt

Mole Conversions

Significant Figures

When a decimal point is present start from the left side

• Once you find the first 90 number that counts, every other number counts

• When a decimal point is not present start from the right side once you find the first non-zero number that counts, every other number counts

Empirical formula

Compound which has been reduced to the lowest term

Ex: So3,CH4, H2O

Single and double replacement reaction

• Single replacement-When an element and a compound are on each side of the arrow

• Double replacement reaction-2 compounds exchange ions with each other, two compounds are in each side

Percent error

Measured value= Experimental value

Molecular formula

1. Find the imperial formula mass

2. Mole formula on table T

3. Multiply imperial formula by answer to step two

Law of conservation of mass

Mass of reactants must be equal to mass of products

Four Chemical Reactions

Synthesis Two or more substances combined to form a compound

Decomposition when a compound breaks into elements or substances

Solubility

The ability of a substance to dissolve

**Solution is made up of two parts**

• Solute:substance being dissolved ex:NaCI

• Solvent: Substance that Is doing the dissolving ex: Water

Table G

Supersaturated: Above the line

Saturated: on the line

Under saturated: under the line

most soluble is the highest curve for that temperature and lowest solubility is the lowest curve for that temperature**

Molarity

The number of moles of solute dissolved in 1 L of solution represents concentration of a solution

Parts per million(ppm)

Commonly used as a measure of small levels of pollutants An air, water, body fluids

Electrolytes

Substances which are soluble and can break up into ions which conduct electricity(ABS-ACID BASE SALTS)

Acid-HCL(AQ) BASE-NaOH(AQ) SALTS-NaCL(AQ)

Nonelectrolyte

Substances which are highly soluble, Poor conductor of electricity, Does not break into ions

Alcohol-CH3OH SUGAR-C6H12O6

Salt/Anti Freeze

When added to H2O freezing point decreases and boiling point increases

Table H:Vapor pressure

Vapor pressure is amount of pressure needed to have a substance boil or turned into vapor/gas. Direct relationship between VP and temp

Propanol boils at the lowest temperature and has the weakest intermolecular forces Ethanoic acid boils at the highest temperature having the strongest intermolecular force of attraction

Kinetic theory of gases

a real gas behaves most like an ideal gas under high temperature and low pressure ex: flat soda

Different molecular structure different Priorities

Substances with the same element like 02 and 03 are both carbon and have different molecular structures in different properties

3 Heat Formulas

Q=m x c x T

Q=Heat M=Mass C=Specific heat value T=Temp change

Q=m x Hf

Q=Heat(kj) m=mass(g) Hf**Heat of Fusion

Q=m x Hv

Q=Heat(kj) m=mass(g) Hv**Heat of Vaporization

Physical vs Chemical Change

Physical change is the same thing on both sides and chemical is new or different form.

Heat

Heat travels from high temperature to low temperature

Mixtures😣

Homogeneous Mixture uniform, same, even distribution of particles throughout

Ex. Anything with (aq) is the answer, KC(aq)

Heterogeneous Mixtures- particles are distributed unevenly throughout.

Ex. Soil, or Salad dressing

Separation of mixtures:A) filtering (insoluble solid) ex. Sand from water. B) boiling or evaporation or distillation, (soluble solid)

ex. such as Salt water, or 2 different liquids) ex. Water and Alcohol

Matter and Energy

Substances- are composed of elements and compounds.

Substances- are composed of elements and compounds.

Compounds- 2 or more different elements, CHEMICALLY combined, CAN be decomposed, FIXED ratio of elements.

Mixtures- 2 or more elements are PHYSICALLY combined, VARIED ratio of elements, can be physically separated.

Combined Gas Law

P1V1/T1 = P2V2/T2

Boyles Law

the relationship between pressure and volume (inverse)

The word constant means to cross out,

In Boyles Law, Temperature is constant.

STP- use Table A for the correct units.

Ex. If 80ml of a gas is compressed from 60kpa to 30 kpa at constant temperature, what is the new volume?

Charles Law

the relationship between temperature and volume. ** Temp has to be in

KELVIN™* YOU must convert CELSIUS into KELVIN by using TEMP FORMULA

the word constant means to cross-out.

Charles Law pressure is constant. V1/T1 = V2/T2

Phase Change Diagram

EQUAL VOLUME= EQUAL # OF MOLECULES

Arrhenius Acid

Gives off H+ or H2O+ hydronium ions in solution

Arrhenius Base

Gives off OH (Hydroxide ions) In solution, metal with an OH ion

Ex: NAOH, Ca OH2

Bronsted-Lowry Acids

Donate H+(Proton) To a base, has one more H+ Ion. An acid on the left-hand side always has a conjugate base on the right hand side

Bronsted-Lowry Bases

Except a proton from an acid, one less H+ ION. A BASE ON THE LEFT HAND SIDE ALWAYS HAS A conjugate ACID ON THE RIGHT HAND SIDE.

Table J

Everything above, H2 reacts with an acid

Everything below H2 does not react with an acid

Kinetics and Equillibrium

Potential Energy- stored energy

Kinetic energy- energy in motion

Activatation energy- energy need to start a reaction

Factor affecting reaction rates

• If you increase the temperature, The number of effective collisions increase thus reaction rate increases.

• If you increase the CONCENTRATION, # of effective collisions increases , thus reaction rate increase

• By increasing the SURFACE AREA, # of effective collisions increase, reaction rate increase the number of reaction sites increases the number of total collisions.

• By adding a CATALYST, the reaction rate increases because the reaction speeds up by lowering the ACtavation energy without getting used up and providing an alternate pathway for the reaction.

Equilibrium

When the forward and reverse reaction of a chemical reaction precedes that equal or same rates

Phase equilibrium

When the rate of the Ford reaction equals rate of reverse reaction

Solution equilibrium

Rates of dissolved equal rates of unsolved(Saturated solution)

Chemical equilibrium

When concentrations of the products and reactants remain constant.

Rates are equal concentrations are constant

Temperature

Decrease your stay increase shift away

Pressure

• Pressure only affects gases

• As the pressure increases, you shift towards the side with less moles

Concentration

As the concentration increase, Shift away from the side where it increase, The side, The concentration always increases.

Concentration increases away(CIA)

Systems of nature

Low energy and high entropy/disorder

Ph Sacle

If a concentration increases by a factor of 10, it decreases by 1, and if a concentration decreases by 10 increases by one