CHM Midterm Flashcards
Law of Conservation of Mass
Mass is neither created nor destroyed
Law of Definite Proportions
A given compound always contains exactly the same proportions of elements by mass
Law of Multiple Proportions
When 2 elements form a series of compounds, the ratios of the masses of the 2nd element that combine w/ 1 gram of the first element can always be reduced to small whole numbers
What is Dalton’s Atomic Theory?
- All elements are composed of atoms
- All atoms of a given element are identical
- Chemical compounds are formed when atoms combine
Thomson Model
Electrons are in a diffuse cloud of positive charge
Millikan Experiment
Determined the charge of the electron
Rutherford Experiment
It is a nuclear atom
Isotopes have the ____ atomic number but _____ mass numbers
Same; different
Covalent Bonds
Atoms sharing electrons
Cation
formed by the loss of electrons; positive charge
Anion
formed by the gain of electrons; negative charge
Ionic bonds
formed by the interaction of cations and anions
In the period table, metals are the ______ and tend to form _____
- Majority
- Cations
Nonmetals tend to form ____
Anions
Type I Binary Compound
Contains a metal and nonmetal that always forms the same cation
Type II Binary Compound
Contains a metal that can form more than one cation
Type III Binary Compound
Contains 2 nonmetals
How do you name a Type I Binary Compound
Its a metal and nonmetal; Name metal, change nonmetal to -ide
How do you name a Type III Binary Compound?
Contains two nonmetals; use prefixes
What are each of the prefixes used for Type III Binary Compounds?
Mono - 1
Di - 2
Tri - 3
Tetra - 4
Penta - 5
Hexa - 6
Hepta - 7
Octa - 8
Nona - 9
Deca - 10
3 or more elements is a _____
Polyatomic Compound
Strong electrolyte
100% dissociated to produce separate ions; strongly conducts an electric current
Weak electrolyte
only a small percentage of dissolved molecules produce ions; weakly conducts an electric current
Nonelectrolyte
Dissolved substance produces no ions; does not conduct an electric current
Strong acid
completely dissociates into separated H+ and anions
Strong base
completely dissociates into separated OH- and cations
Weak acid
dissociates to a slight extent
Weak base
results in a solution that is a weak electrolyte & contains OH- ions
Acid-base reactions
involve a transfer of H+ ions
Precipitation Reactions
Formation of a solid occurs
Oxidation-Reduction Reactions
Involve electron transfer
Oxidation
Increase in oxidation state (loss of electrons)
Reduction
Decrease in oxidation state (gain of electrons)
Oxidizing agent
gains electrons (is reduced)
Reducing agent
loses electrons (is oxidized)
What are the steps to half-reaction method in acid?
- Assign Oxidation States
- Split into oxidation and reduction formulas
- For each formula
a. make sure all elements are balanced except O and H
b. Balance O with H2O
c. Balance H with H+
d. Use electrons to equalize oxidation states on both sides - Combine and eliminate like substances
What are the steps to half-reaction method in base?
- Do everything in acid
- Add the number of OH- ions that are equal to number of H+ ions on both sides
- Form H2O on the side containing both H+ and OH- ions, and eliminate the number of H2O molecules that appear on both sides of the equation
- Check that the elements and charges balance
Boyle’s Law
Pressure is inversely proportional to volume
Charles’ Law
Volume at constant pressure is directly proportional to the temperature
Avogadro’s Law
Equal volumes of the gases at the same temperature and pressure contain equal number of molecules
What are the postulates of the Kinetic Molecular Theory?
- Volume of gas particles is negligible (zero)
- No particle interactions
- Particles are in constant motion, colliding w/ container walls to produce pressure
- The average kinetic energy of gas particles is directly proportional to the Kelvin temperature of the gas
Diffusion
the mixing of two or more gases
Effusion
the process in which a gas passes through a small hole into an empty chamber
What is Real Gas Behavior?
- Real gases approach ideal behavior at high temperatures and low pressures
- Understanding how the ideal gas law must be modified to account for real gas behavior helps us understand how gases behave on a molecular level
- Van der Waals found that to describe real gas behavior, we must consider particle interactions and particle volumes
Le Chatelier’s Principle
If a change in conditions is imposed on a system at equilibrium, the system will shift in a direction that compensates for imposed change
