General Chemistry Ch 4. Compounds and Stoichiometry

Question 1

Compounds

Answer 1

Substances composed of two or more elements in a fixed proportion

Question 2

Molecular weight

Answer 2

The mass (in amu) of the constituent atoms in a compound as indicated by the molecular formula

Question 3

Molar mass

Answer 3

The mass of one mole of a compound, usually measured in grams per mole

Question 4

Gram equivalent weight

Answer 4

A measure of the mass of a substance that can donate one equivalent of the species of interest

Question 5

Normality

Answer 5

The ratio of equivalents per liter, related to molarity by multiplying the molarity by the number of equivalents present per mole of compound

Question 6

Molarity

Answer 6

-

Question 7

Equivalents

Answer 7

Moles of the species of interest, equivalents are most often seen in acid-base chemistry and oxidation reduction reactions

Question 8

Law of constant composition

Answer 8

States that any pure sample of a compound will contain the same elements in the same mass ratio

Question 9

Empirical formula

Answer 9

The smallest whole number ratio of the elements in a compound

Question 10

Molecular formula

Answer 10

Either the same as or a multiple of the empirical formula, gives the exact number of atoms of each element in a compound

Question 11

Percent composition of mass

Answer 11

Divide the mass of the individual element by the molar mass of the compound

Question 12

Combination reactions

Answer 12

When two or more reactants combine to form one product

Question 13

Decomposition reactions

Answer 13

When one reactant is chemically broken down into two or more products

Question 14

Combustion reactions

Answer 14

Occur when a fuel and an oxidant react, forming the products water and carbon dioxide

Question 15

Displacement reactions

Answer 15

When one or more atoms or ions of one compound are replaced with one or more atoms or ions of another compound

Question 16

Single-displacement reactions

Answer 16

Occur when an ion of one compound is replaced with another element

Question 17

Double-displacement reactions

Answer 17

Occur when elements from two different compounds trade places with each other to form two new compounds

Question 18

Neutralization reactions

Answer 18

Those in which an acid reacts with a base to form a salt (and usually water)

Question 19

Balanced equations determination steps

Answer 19

1. Balancing the least common atoms
2. Balancing the more common atoms (H and O)
3. Balancing charges if necessary

Question 20

Limiting reagent

Answer 20

The reactant that will be consumed first in a chemical reaction

Question 21

Excess reagents

Answer 21

Reactants that are not consumed first in a chemical reaction

Question 22

Theoretical yield

Answer 22

The amount of product generated if all of the limiting reactant is consumed with no side reactions

Question 23

Actual yield

Answer 23

Typically lower than the theoretical yield

Question 24

Percent yield

Answer 24

Actual yield divided by theoretical yield and converting to a percentage

Question 25

Roman numerals ions

Answer 25

Used for non representative elements to donate ionic charge

Question 26

-ous ending

Answer 26

Used to indicate lesser charge

Question 27

-ic ending

Answer 27

Used to indicate greater charge

Question 28

-ide ending

Answer 28

End all monatomic anions

Question 29

Oxyanion suffixes

Answer 29

Indicate how oxidized the central atom is, those with a lesser amount of oxygen are given the suffix -ite and those with a greater amount are given the suffix -ate

Question 30

Oxyanion prefixes

Answer 30

For oxyanion series with more than two members, the species with the fewest oxygens is given the prefix hypo- and the species with the most oxygens is given the prefix per-

Question 31

Polyatomic ions containing hydrogen

Answer 31

Denote the number of hydrogens using hydrogen to denote one or dihydrogen to denote two

Question 32

Ionic charges

Answer 32

Predictable by group number and type of element (metal or nonmetal) for representative elements, but are generally unpredictable for non representative elements

Question 33

Metal ionic charge

Answer 33

Form positively charged cations based on group number

Question 34

Nonmetal ionic charge

Answer 34

From negatively charged anions based on the number of electron needed to achieve an octet

Question 35

Electrolytes

Answer 35

Contain equivalents of ions from molecules that dissociate in solution, the strength of an electrolyte depends on its degree of dissociation or salvation