CHM Midterm

Question 1

Law of Conservation of Mass

Answer 1

Mass is neither created nor destroyed

Question 2

Law of Definite Proportions

Answer 2

A given compound always contains exactly the same proportions of elements by mass

Question 3

Law of Multiple Proportions

Answer 3

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

Question 4

What is Dalton’s Atomic Theory?

Answer 4

1. All elements are composed of atoms
2. All atoms of a given element are identical
3. Chemical compounds are formed when atoms combine

Question 5

Thomson Model

Answer 5

Electrons are in a diffuse cloud of positive charge

Question 6

Millikan Experiment

Answer 6

Determined the charge of the electron

Question 7

Rutherford Experiment

Answer 7

It is a nuclear atom

Question 8

Isotopes have the ____ atomic number but _____ mass numbers

Answer 8

Same; different

Question 9

Covalent Bonds

Answer 9

Atoms sharing electrons

Question 10

Cation

Answer 10

formed by the loss of electrons; positive charge

Question 11

Anion

Answer 11

formed by the gain of electrons; negative charge

Question 12

Ionic bonds

Answer 12

formed by the interaction of cations and anions

Question 13

In the period table, metals are the ______ and tend to form _____

Answer 13

1. Majority
2. Cations

Question 14

Nonmetals tend to form ____

Answer 14

Anions

Question 15

Type I Binary Compound

Answer 15

Contains a metal and nonmetal that always forms the same cation

Question 16

Type II Binary Compound

Answer 16

Contains a metal that can form more than one cation

Question 17

Type III Binary Compound

Answer 17

Contains 2 nonmetals

Question 18

How do you name a Type I Binary Compound

Answer 18

Its a metal and nonmetal; Name metal, change nonmetal to -ide

Question 19

How do you name a Type III Binary Compound?

Answer 19

Contains two nonmetals; use prefixes

Question 20

What are each of the prefixes used for Type III Binary Compounds?

Answer 20

Mono - 1
Di - 2
Tri - 3
Tetra - 4
Penta - 5
Hexa - 6
Hepta - 7
Octa - 8
Nona - 9
Deca - 10

Question 21

3 or more elements is a _____

Answer 21

Polyatomic Compound

Question 22

Strong electrolyte

Answer 22

100% dissociated to produce separate ions; strongly conducts an electric current

Question 23

Weak electrolyte

Answer 23

only a small percentage of dissolved molecules produce ions; weakly conducts an electric current

Question 24

Nonelectrolyte

Answer 24

Dissolved substance produces no ions; does not conduct an electric current

Question 25

Strong acid

Answer 25

completely dissociates into separated H+ and anions

Question 26

Strong base

Answer 26

completely dissociates into separated OH- and cations

Question 27

Weak acid

Answer 27

dissociates to a slight extent

Question 28

Weak base

Answer 28

results in a solution that is a weak electrolyte & contains OH- ions

Question 29

Acid-base reactions

Answer 29

involve a transfer of H+ ions

Question 30

Precipitation Reactions

Answer 30

Formation of a solid occurs

Question 31

Oxidation-Reduction Reactions

Answer 31

Involve electron transfer

Question 32

Oxidation

Answer 32

Increase in oxidation state (loss of electrons)

Question 33

Reduction

Answer 33

Decrease in oxidation state (gain of electrons)

Question 34

Oxidizing agent

Answer 34

gains electrons (is reduced)

Question 35

Reducing agent

Answer 35

loses electrons (is oxidized)

Question 36

What are the steps to half-reaction method in acid?

Answer 36

1. Assign Oxidation States
2. Split into oxidation and reduction formulas
3. 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
4. Combine and eliminate like substances

Question 37

What are the steps to half-reaction method in base?

Answer 37

1. Do everything in acid
2. Add the number of OH- ions that are equal to number of H+ ions on both sides
3. 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
4. Check that the elements and charges balance

Question 38

Boyle’s Law

Answer 38

Pressure is inversely proportional to volume

Question 39

Charles’ Law

Answer 39

Volume at constant pressure is directly proportional to the temperature

Question 40

Avogadro’s Law

Answer 40

Equal volumes of the gases at the same temperature and pressure contain equal number of molecules

Question 41

What are the postulates of the Kinetic Molecular Theory?

Answer 41

1. Volume of gas particles is negligible (zero)
2. No particle interactions
3. Particles are in constant motion, colliding w/ container walls to produce pressure
4. The average kinetic energy of gas particles is directly proportional to the Kelvin temperature of the gas

Question 42

Diffusion

Answer 42

the mixing of two or more gases

Question 43

Effusion

Answer 43

the process in which a gas passes through a small hole into an empty chamber

Question 44

What is Real Gas Behavior?

Answer 44

1. Real gases approach ideal behavior at high temperatures and low pressures
2. 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
3. Van der Waals found that to describe real gas behavior, we must consider particle interactions and particle volumes

Question 45

Le Chatelier’s Principle

Answer 45

If a change in conditions is imposed on a system at equilibrium, the system will shift in a direction that compensates for imposed change