Flashcards in General Chemistry Chapter 4: Compounds and Stoichiometry Deck (21)
What are compounds?
Substances composed of two or more elements in a fixed composition
What is molecular weight?
Mass (in amu) of the constituent atoms in a compound as indicated by the molecular formula.
What is molar mass?
Mass of one mole (6.022 x 10^23 particles) of a compound
What is gram equivalent weight?
Measure of the mass of a substance that can donate one equivalent of the species of interest.
What is the normality?
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
What are equivalents?
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).
What is the law of constant composition?
states that any pure sample of a compound will contain the same elements in the same mass ratio.
What is the empirical formula?
Smallest whole-number ration of the elements in a compound
What is the molecular formula?
Either the same as or a multiple of the empirical formula; it gives the exact number of atoms of each element in a compound.
How do you calculate the percent composition by mass?
Determine the mass of the individual element and divide by the molar mass of the compound .
What are combination reactions?
Occur when two or more reactants combine to form one product
What are decomposition reactions?
Occurs when one reactant is chemically broken down into two or more products.
What are combustion reactions?
occur when a fuel and an oxidant (typically oxygen) react, forming the products water and carbon dioxide. (if the fuel is a hydrocarbon)
What are displacement reactions?
Occur when one or more atoms or ions of one compound are replaced with one or more atoms or ions of another compound.
What are neutralization reactions?
those in which an acid reacts with a base to form a salt ( and, usually water)
In what order do you balance equations?
1. least common atoms
2. more common atoms (hydrogen and oxygen)
3. charge, if necessary
-ous vs. -ic
-ous = lesser charge, -ic = greater charge
What do monatomic things end in?
-ite vs. -ate
lesser amount of oxygen = ite
greater amount = ate
Oxyanions with more than two members are given an additional level. hypo- vs. per-
Fewest oxygens = hypo-
Greatest = per-