Review Flashcards
Density = ?
Mass/ Volume
Intensive Property
Does NOT depend on the quantity of matter present
Ex: Density, Temp.
Extensive Property
Depends on the quantity of matter present
Ex: Volume, Mass
Law of Conservation of Mass
Mass cannot be created nor destroyed
Law of Definite Proportions
Every sample of the same compound has the same constituent elements present in the same ratio.
Ex: H2O 2 H atoms 1 O atom
Law of Multiple Proportions
If two compounds contain the same elements, they are present in different ratios in each different compound
Ex: H2O vs H2O2 – both contain H & O but in different ratios
Dalton’s Atomic Theory 1.
All matter consists of atoms. Atoms= indivisible particles of an element
Dalton’s Atomic Theory 2.
All atoms of a given element are identical
NOT TRUE NOW –> Isotopes
Dalton’s Atomic Theory 3.
Atoms of a given element can NOT be converted into atoms of a different element.
Not true now because of nuclear chemistry
Dalton’s Atomic Theory 4.
Compounds are the result of combinations of atoms of different elements
–remember law of definite proportions and law of multiple proportions
Dalton’s Atomic Theory 5.
Chemical reactions are the result of separation, combination, or rearrangement of atoms – do NOT result in atom creation or destruction
–remember law of conservation of mass
Dalton did NOT
did not give a picture of atoms and did not discuss structure of atoms.
Isotopes of the same element..
have varying number of neutrons
Inside the nucleus
proton & neutron
Outside the nucleus
electron
Proton
+1 charge
Positively charged subatomic particles
Relative mass= 1 amu
Neutron
no charge
Subatomic particle that has no charge
Relative mass= 1 amu
AMU
Atomic Mass Unit
Electron
-1 charge
Negatively charged subatomic particle
Relative mass= 0 amu
Atomic #
of protons in the nucleus
(for neutral atoms # of protons = # of neutrons
Atomic Mass #
Sum of # of protons and neutrons
Naturally occurring (in nature) percentage of each isotope of each element
Natural Abundance
Always monoatomic
Noble gases
Diatomic elements
H2, N2, O2, F2, Cl2,Br2, I2
If an atom gains or loses electrons, it becomes charged
Ions
Cation
result of an atom losing e- (+)
Anion
result of an atom gaining e- (-)
Main group # indicates ___
of e- in outermost shell (valence e-)
Atoms gain or lose e- to form ions with 8 ___ e-
valence
Magic # of stability
8
Outer shell
Valence shell
indicate charge of ion as roman numeral after the element name
Stock Notation
____ have the ability to form cations of multiple charges
Transition metals
result of electrostatic attraction of metal cation and non-metal anion
Ionic Compounds
____ result of e- transfer from metal cation to non-metal anion
ionic compounds
_____ combine in such a way that the resulting ionic compound is neutral
metal cations and non-metal anions
1
Mono
2
Di-
3
Tri-
4
Tetra-
5
Penta-
6
Hex-
7
Hepta-
8
Octa-
9
Nona-
10
Deca-
Covalent compounds
result of 2 non-metal elements combining
Polyatomic ions
consist of two or more atoms that collectively have a charge –> act as a unit
Tells you exact # of every element in a substance
Chemical Formula
Only gives the smallest whole # ration of each element present in a compound (can be useful experimentally)
Empirical Formula
Molecular weight – accounts for the mass of ALL atoms in a molecule/compound
Molar Mass
Ionic compound uses ____ method
cross down
covalent compound uses ___ method
greek prefixes
Transition metals uses ___ method
cross up
Molar Mass =
Grams/ Mole
There is no direct conversion from grams –> atoms must go through ____.
Moles
_____ are the complete sentences of chemistry and outline what happens in a chemical reaction
Balanced chemical equations
Reactants
Starting material of the reaction
Products
End result of the reaction
____ are used to balance chemical equations
Stoichiometric coefficients
_____ give mole:mole rations of reactants to products in balanced chemical equations
Stoichiometric coefficients
Using balanced chemical equations to do mole mass conversations for reactants and products
Stoichiometry
The reactant that LIMITS how much product can be found in a reaction (assuming you did the rxn perfectly)
Limiting reagent
Max amount of product that can be formed; based on the amount of limiting reagent used (assuming no errors)
Theoretical yield
Actual yield from a reaction when performed in the lab
Experimental yield
% yield
experimental yield/theoretical yield X 100
Percent yield goal
High
Percent error goal
Low
To determine amount of excess reagent remaining after the rxn is complete, you first need to determine how much _____ you should have used
Excess reagent
Precipitate
insoluble solid
Electrolytic solutions
capable of conducting electricity
All ionic substances that are soluble in H2O produce ___.
Ex: NaCl in H2O
electrolytic solutions
Non-electrolytic solutions
Ex. Sugar in H2O
do NOT conduct electricity
Soluble
Will dissolve
Insoluble
Will not dissolve
ionization AKA
dissociation
separation of a substance into ions (cations & anions)
Ex: NaCl —H2O—> Na+ + Cl-
Ionization
Completely ionize/dissociate
Ex: CaCl2 —-H2O—> Ca2+ + 2Cl-
strong electrolytes
Incompletely dissociate/ionize
Ex: H20 H+ + OH-
weak electrolytes
____ form insoluble products (precipitates)
Precipitation rxns
Formation of a _____ is based on solubility of products.
precipitates
Spectator ions
- do NOT participate in the real chemistry
- are NOT chemically changed from reactant –> product side of rxn.
Net ionic equation
REAL chemistry
Aqueous =
H2O
Solution
Homogeneous mixturen of a solute and a solvent
Solute
Substance being dissolved by solvent
Unsaturated solution
Contains a minimum of solute that the five amount of solvent is capable of dissolving
Saturated solution
contains maximum amount of solute that given amount of solvent is capable of dissolving
super-saturated solution
contains more solute that the given amount of solvent is capable of dissolving
Arrhenius acid
substance that ionizes in H2O to give H+
Arrhenius base
substance that ionizes in H2O to give OH-
Polyprotic acids
Step-wise dissociation of H+
Weak Acids
Incompletely disociate
Bronsted acid
proton donor = H+ donor
Bronsted base
proton acceptor = H+ acceptor
Amphoteric
substance that can act as both an acid or base
Strong bases undergo _____
complete —–> dissociation
Weak bases undergo _______
incomplete dissociation
All Arrhenius acids are also classified as
Bronsted acids
Acid-base titrations
analytical method for determining concentration of an unknown acid or base
For acid-base titrations you must know _____
the concentration of either the acid or the base, then can experimentally determine the concentration of the other one.
Equivalence point
point in titration when stoichiometric equivalence of solution of known concentration has been added to solution of unknown concentration of complete rxn
End point
point in titration when indicator changes color
Goal in titration
want end point to be as close to equivalence point as possible