Maleckar
2016-2017
Exam 1 Review Sheet
CHS Chemistry
Chapter 1: Matter, Measurement, and Problem Solving
 how many significant digits are present in a number
 report an answer with the correct number of significant digits
 write numbers in scientific notation
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Chapter 2: Atoms, Molecules, and Ions
Dalton’s Atomic Theory
know what Dalton thought about the structure of an atom
understand Thomson’s model for an atom
understand Rutherford’s model for an atom and how his experiments showed this
know what contribution Milliken made
know the structure of an atom and where the most mass is, where most volume is, where the charges are
know how to abbreviate the symbol for an atom using nuclide notation and hyphen notation ex: 126C Carbon-12
 superscript = mass number = protons + neutrons
 subscript = atomic number = # protons
know how to calculate #protons/neutrons/electrons given the symbol & numbers
know what an isotope is (differ in # of neutrons, not electrons or protons)
be able to calculate average atomic masses when given their % abundances; do other similar problems regarding
isotopes
understand the layout of the periodic table
Alkali Metals, Alkaline Earth Metals, Halogens, Noble Gases, Transition Metals, Lanthanides, Actinides, Metals,
Nonmetals, Metalloids
be able to convert between grams/moles/atoms; understand the mole and be proficient with Avogadro’s number
know what an ion is
know the difference between a cation and an anion
be able to predict the charges of ions: Group 1A atoms form +1 cations; Group 2A atoms form +2 cations; Al
forms a +3 cation; N forms a -3 anion; Group 6A atoms form -2 anions; Group 7A atoms form -1 anions; charges
on transition metals - there are too many possibilities
be able to tell the difference between ionic and covalent compounds by looking at their formulas
be able to determine the oxidation number of an atom from a formula (ex: Cu in CuSO4 is +2)
be able to create a neutral ionic compound from cations and anions, using the appropriate subscripts
be able to name compounds
Ionic Compounds
- metal/nonmetal where metal has a fixed & predictable charge: ex: LiCl lithium chloride
- metal/nonmetal where metal is a transition metal: ex: FeCl2 iron(II) chloride
Molecular Compounds
- nonmetal/nonmetal use prefixes (know 1-10) ; no “mono” in front of the first element
ex: SO3 sulfur trioxide
Acids
- oxyanions/oxyacids/ternary acids
-ate ending on the anion becomes an –ic ending on the acid
Ex:
NO3- nitrate
HNO3 nitric acid
-ite ending on the anion becomes an –ous ending on the acid
Ex:
NO2- nitrite
HNO2 nitrous acid
Hydrates
- Name the ionic compound, then use the prefix + hydrate to indicate the quantity of water molecules
Ex: Magnesium Sulfate Heptahydrate MgSO4  H2O
Chapter 3: Calculations with Chemical Formulas and Chemical Equations
 be able to balance reactions (except for redox reactions)
 understand what a redox reaction is (some atoms are changing their charges, gaining and losing electrons)
 be able to calculate molecular weights for compounds from their formulas
 be able to calculate % composition (by mass or by mole) of individual elements in a compound
 be able to apply Avogadro’s number to get # of atoms
 be able to determine empirical formulas & molecular formulas, given %s or amounts in grams
 moles in = moles out and mass in = mass out (Law of Conservation of Mass)
 be able to do combustion analysis problems
Chapter 4: Chemical Reactions
 know what an electrolyte is; know what a nonelectrolyte is
 know the difference between a strong and weak electrolyte
Substance that breaks apart completely to make ions is a strong electrolyte
Substance that breaks apart a little bit to make ions is weak electrolyte
Substance that doesn’t generate ions at all is a non-electrolyte
 be able to recognize/complete the following types of reactions:
combustion: hydrocarbon (C, H, maybe O) + O 2  CO2 + H2O oxygen is a reactant
metathesis/Double displacement: AB + CD  AD + CB 2 ionic compounds
single replacement AB + C  A + CB element +compound
combination/synthesis/composition: A + B  C 1 product
decomposition: C  A + B
1 reactant
 Special Double Displacement Reactions
neutralization: HX + YOH  YX + H2O acid + base = salt + water
precipitation reaction
 Metathesis reactions can be driven to completion by the formation of a pure substance
 the formation of a gas product (H2S, CO2, N2, O2, H2, H2CO3, SO2, or NH3)(
Further decompose
H2CO3  H2O + CO2
H2SO3  H2O + SO2
NH4OH H2O + NH3
 the formation of a precipitate (ppt, s or ↓)
 a difference in activities of metals
use provided activity series – the higher the metal is on the list, the stronger reactant that metal will be
 redox reactions can be spotted by assigning oxidation numbers to all of the atoms in the reaction; if something
changes oxidation numbers from one side of the reaction to the other, then it has gained/lost electrons; OIL RIG;
both an oxidation and a reduction must take place in the same reaction
 be able to write complete and net ionic equations:
the ions that cancel out are the spectator ions
the remaining “stuff” is the net ionic equation
 be able to calculate molarity (moles/liter)
 be able to do dilution problems using molarity M1V1 = M2V2