Advanced Chemistry Semester I Review

Never forget anything! Much of this will come back to haunt you second semester!

Advanced Chemistry Semester I Review

Ch. 1 ChemThink: Particulate Nature of Matter (in introduction)

·  physical properties/physical change (same substances)

·  chemical properties/chemical change (new substance made: evidence of chemical change may include production of a gas, formation of a solid (precipitate), light, new temp, new color)

·  mixture/pure substance (mixtures can be separated into different substances by physical means like filtering. Pure substances cannot be separated into different substances using physical means.)

·  heterogeneous (mixture not uniform) & homogeneous mixtures (uniform)

·  element (one symbol from periodic table) /compound (>1 symbol from periodic table)

·  states of matter and endothermic vs exothermic phase changes (sßàl = melting, sßàg = subliming etc.)

·  products, reactants, identifying a chemical reaction

Ch. 2 ChemQuests 2a, 2b and 2c

·  Dimensional analysis: cancel units! show set-up!

·  significant figures: In a measurement all certain digits plus the guessed digit are all significant.

·  Calculations with sig. figs.: 1. nonzero digits are always sig. 2. Any zeros between sig figs are sig. 3. trailing zeros in the decimal portion ONLY are sig. 4. Adding/subtracting: round to the place of the least certain digit. 5. Multiply/divide keep fewest # of sig figs

·  scientific notation

·  metric system: know conversions between meters, km, cm and mm (grams, kg, cg, mg, liters, kL, mL, cL)

·  measurements are always made so that there is one and only one estimated digit.

·  accuracy – how close to truth. precision – how close several measurements are to each other

·  Error and percent error - (error = your answer – accepted value) (Percent error = erroraccepted x 100)

·  Density and specific heat calculations q = mCΔT where q = energy in Joules, m = mass in grams, C = specific heat in J/g°C and ΔT = change in temperature in Celsius

Ch. 3 Average Atomic Mass, ChemThink: The Atom, Isotopes, Ions, Trendsetter activity

·  Rutherford’s famous gold foil experiment (Showed that nucleus was tiny compared to the size of the atom & also positively charged)

·  atomic # (# of protons), mass # (# protons + neutrons), # of e- (same as # protons if neutral atom, the number of protons - # electrons = charge of an ion)

·  average atomic mass on the periodic table is in amu if you are talking about 1 atom, and in grams if you are talking about 6.022 x 1023 atoms.

·  isotopes & relative abundance (% A) (mass of A) + (% B) (mass of B) … = average mass of all isotopes

·  Periodicity (elements in the same column behave similarly), Mendeleev

·  Periodic trends in atomic radius and 1st ionization energy caused by nuclear charge.

·  metals, nonmetals, metalloids, noble gases, halogens, alkali metals, alkaline earth metals

·  group, period

·  estimate properties based on position in periodic table

·  NEVER FORGET your element symbols!

Ch. 4 ChemQuest #10 (light, Bohr problems) Argumentation: Energy and the Electron, Electron Energy & Light

·  electromagnetic spectrum (radio/TV waves, microwaves, IR, red, orange…violet, UV, x rays, gamma)

·  wavelength λ, E = energy. E = hcλ, where c = the speed of EM radiation: 2.998 x 108 m/s and h = Planck’s constant: 6.626 x 10-34 J.s.

·  s, p, d & f orbitals & s, p, d & f blocks on the periodic table

·  orbital diagrams and electron configurations – fill lowest energy levels first, 2 e- in each orbital but follow bus seat (Hund’s) rule.

Ch. 5 Ionic Bonding: sections 5.1 & 5.7 ChemQuest #19, 20, 21 & 26, ChemThink: Ions, Ionic Bonding & Ionic Formulas

·  ions form by gaining or losing electrons in order to attain noble gas electron configuration

·  Oppositely charged ions are attracted to each other & will form compounds that are neutral – usually a metal and a nonmetal.

·  the ratio of positive to negative ion becomes the subscripts in the formula

·  Cations (positive ions) are ALWAYS written first in the formula and in the name

·  name each ion – cations are named with the element name. All transition metals except silver, zinc and cadmium need Roman numerals showing their charges. Monatomic anions end in the suffix –ide, polyatomic ions have their own names that you will NEVER FORGET!

Covalent bonding: sections 5.2 – 5.5, 5.7 ChemQuest # 24 ChemThink: Covalent Bonding

·  diatomic elements: H2, N2, O2, F2, Cl2, Br2, I2

·  covalent = atoms trying to take each others’ electrons – looks like sharing electrons – usually made up of nonmetals

·  Name using prefixes, mono, di, tri, tetra, pent, hex, hept, oct, non, dec.

·  Lewis diagrams show all valence electrons and give each atom a full outer energy level. Double & triple bonds may be necessary.

·  resonance structures – several possible Lewis diagrams for a molecule - each with double bond in a different position.

·  calculate bond order to determine relative bond strength and bond length

Chapter 6 ChemThink: Molecular Geometry, ChemQuest # 27, PhET: Molecule Shapes and Molecular Polarity

·  VSEPR for molecular geometry. Bond angles are dependent on the number of electron regions surrounding the central atom.

·  use electronegativity to determine whether a bond between nonmetals and/or metalloids is nonpolar covalent, polar covalent or ionic. (ΔEN 0.0 - 0.4 = nonpolar covalent, ΔEN greater than 0.4 up to 2.0 = polar covalent, ΔEN greater than 2.0 or metal and nonmetal = ionic)

Other things to consider:

·  lab practical included as part of your exam grade—dress in long pants and closed toed shoes

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Never forget anything! Much of this will come back to haunt you second semester!