General Chemistry Chapter 4: Compounds and Stoichiometry

Question 1

What are compounds?

Answer 1

Substances composed of two or more elements in a fixed composition

Question 2

What is molecular weight?

Answer 2

Mass (in amu) of the constituent atoms in a compound as indicated by the molecular formula.

Question 3

What is molar mass?

Answer 3

Mass of one mole (6.022 x 10^23 particles) of a compound

Question 4

What is gram equivalent weight?

Answer 4

Measure of the mass of a substance that can donate one equivalent of the species of interest.

Question 5

What is the normality?

Answer 5

the ratio of equivalents per liter; it is related to molarity by multiplying the molarity by the number of equivalents present per mole of compound

Question 6

What are equivalents?

Answer 6

Moles of the species of interest; equivalents are most often seen in acid-base chemistry (hydrogen ions or hydroxide ions) and oxidation-reduction reactions (moles of electrons or other ions).

Question 7

What is the law of constant composition?

Answer 7

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

Question 8

What is the empirical formula?

Answer 8

Smallest whole-number ration of the elements in a compound

Question 9

What is the molecular formula?

Answer 9

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

Question 10

How do you calculate the percent composition by mass?

Answer 10

Determine the mass of the individual element and divide by the molar mass of the compound .

Question 11

What are combination reactions?

Answer 11

Occur when two or more reactants combine to form one product

Question 12

What are decomposition reactions?

Answer 12

Occurs when one reactant is chemically broken down into two or more products.

Question 13

What are combustion reactions?

Answer 13

occur when a fuel and an oxidant (typically oxygen) react, forming the products water and carbon dioxide. (if the fuel is a hydrocarbon)

Question 14

What are displacement reactions?

Answer 14

Occur when one or more atoms or ions of one compound are replaced with one or more atoms or ions of another compound.

Question 15

What are neutralization reactions?

Answer 15

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

Question 16

In what order do you balance equations?

Answer 16

1. least common atoms
2. more common atoms (hydrogen and oxygen)
3. charge, if necessary

Question 17

-ous vs. -ic

Answer 17

-ous = lesser charge, -ic = greater charge

Question 18

What do monatomic things end in?

Answer 18

-ide

Question 19

-ite vs. -ate

Answer 19

lesser amount of oxygen = ite

greater amount = ate

Question 20

Oxyanions with more than two members are given an additional level. hypo- vs. per-

Answer 20

Fewest oxygens = hypo-

Greatest = per-

Question 21

What are electrolytes?

Answer 21

Contain equivalents of ions from molecules that dissociate in solution. The strength of an electrolyte depends on its degree of dissociation or solvation.