Honors Chemistry Final Exam Review

Dalton

Diagram: Billiard Ball Model, Solid, Individual spheres that can bond

Evidence: Priestley Lavoisier + Diamond experiments

Justification: Compounds can be broken apart into simpler substances. Simpler Substances can combine in fixed ratios. In both cases, new properties emerge

Thomson

Diagram: Chocolate Chip Cookie Model, small negatively charged electrons and positive charged spread spread throughout

Evidence: Cathode Ray Experiments

Justification: The Cathode Ray itself is a beam of electrons. It moves away from the negative end of the magnet. Light dosen’t do that, Matter does.

Rutherford

Diagram: Most of the atom is empty space, Positive charge is condensed in the nucleus

Evidence: Gold Foil Experiment

Justification: Most positively charged alpha particles passed right through the gold. The small % that were deflected off that straight path did so because they approached the dense positive nucleus.

Bohr

Diagram: Electrons orbit the nucleus at specific distances (energy levels)

Evidence: Line Emission Spectra

Justification: Electrons jump up to higher energy levels when they absorb energy. When they fall back down, they release energy we can see as light. Each line on the spectrum is a specific fall an electron made. They only have specific colors (not all wave-lengths)

Electronegativity

The tendency to attract electrons

Nonpolar covalent bond

• X < 0.3

• e- spends equal time around each atom (equal sharing)

Polar Covalent Bond

• 0.3 < X < 1.67

• e- are shared

Ionic bond

• X > 1.67

• e- are transferred from metal to non-metal

molecular Compound

• Low melting and boiling point

• Individual molecules

• Poor conductor

Ionic compound

• High melting and boiling point

• Complex crystal lattic

• Good Conductor when liquid or dissolved

Anion

an atom that has more electrons than protons

• an atom with a negative charge

Cation

a positively charged ion that is formed when a metallic element loses one or more electrons.

• positive charge

Mono = 1

Di = 2

Tri = 3

Tetra = r

Penta = 5

Hexa = 6

Hepta = 7

Octa = 8

Nona = 9

Deca = 10

Mono =

Di =

Tri =

Tetra =

Penta =

Hexa =

Hepta =

Octa =

Nona =

Deca =

Relative Mass

Mass relative to (compared to) the least massive item in the comparison group

Molar Mass

Mass of one mole of a substance; found on periodic table

Br H O F I N Cl

Diatomic Elements

Empirical formula

Is the simplest ratio of elements in a compound based on experimental evidence

Molecular formula

Is the actual mole ratio of elements in a compound based on the amount and empirical formula

Coefficient

Subscript

Double Replacement

A reaction in which the positive and negative ions of 2 ionic compounds exchange places to form 2 new compounds

• FeS + 2HCI —> H₂S + FeCl₂

Combustion

A carbon compound is burned in oxygen to form carbon dioxide and water

( Carbon compound + O₂ —> CO₂ + H₂O )

• CH₄ + 2O₂ —> CO₂ + 2H₂O

Synthesis

Reaction in which multiple reactants combine to form a single product

( Exothermic)

• N₂ + 3H₂ —> 2NH₃

Decomposition

Reaction in which one reactant breaks down into 2 or more products

( Endothermic)

• 8Li₂S —> 16Li + S₈

Single Replacement

Reaction in which a single, more reactive element replaces an element in a compound, producing a new compound and a pure element

• ZnBr₂ + F₂ —> ZnF₂ + Br₂

• Color change

• New Odor or Texture

• Bubbling/Smoke/Gas (Effervescence)

• Release of light

• Solid form from liquid mixture (precipitate)

What are some examples of evidence that a chemical reaction has taken place?

energy in reactions

All chemical reactions absorb and release energy

• Breaking bonds require an input of energy (Endothermic)

• Making new bonds release energy (Exothermic)

  • Eth-Motion of particles

  • Eph-Spacing of particles

  • Ech-Bonding within particles

• Atoms rearrange

• Total # of atoms involved stays the same

• Reactant bonds are broken, product bonds are formed

• No matter (atom) is created or destroyed. All atoms are accounted for before (reactants side) and after (products side)

Describe key characteristics of all chemical reactions.

Stoichiometry

Using mole rations in a balanced equation to answer: How much do I need? How much can I make?

Theorectical Yield

If nothing does wrong the amount of product you can produce

Acids

H+ Donor

• Low pH

• Sour

• Reaction to Mg

• Reaction with baking soda

• No reaction with lemon

• Good conductors (have ions)

Base

H+ Acceptor

• High pH

• Bitter

• No reaction with Mg

• No reaction with baking soda

• Turned a different color with PTP

• Good conductors (have ions)

Solute

The substance that is dissolved

Solvant

The thing in which the substance is dissolved in

Strength

Degree to which it ionizes

Concentration

Measured in Molarity (M)

Strong Acids

• HCl - Hydrochloric Acid

• HNO3 - Nitric

• H2SO4- Sulfuric

• HClO4 - Perchloric

• HClO3 - Chloric

• HBr - Hydrbromic

• HI - Hydroidoic

Atomic Number

Is determined by the amount of protons

Mass number

Is determined by Neutrons + Protons

Element Symbol

Is determined by the amount of protons

Isotopes

Same amount of protons but different amount of neutrons

Mass Spectrometer

• to analyze the composition of a sample by measuring the mass-to-charge ratio of ions produced from it

• Bigger particles are harder to deflect of their path