Chapter 4: Compounds and Stoichiometry Flashcards
________ ________ is the weighted average of the masses of the naturally occurring isotopes of an element, not their weights.
Atomic weight
____________ ________ is the sum of the atomic weights of all the atoms in a molecule, and its units are atomic mass units (amu) per molecule.
molecular weight
____________ ________ of an ionic compound is found by adding up the atomic weights of the constituent ions according to its empirical formula, and its units are also amu per molecule.
formula weight
molecular weight isn’t really a thing, so we use this
A ________ is equal to the number of particles found in 12 grams of carbon-12.
mole
What are the units for molar mass?
g/mol
What are the units for molecular weight?
amu per molecule
The amount of a compound, measured in grams, that produces 1 equivalent of the particle of interest is called the ________ ________________ ____________.
gram equivalent weight
The ________________ ________ of a compound is the mass that provides 1 mole of the particle of interest.
equivalent weight
________________ is a measure of concentration, given in the units equivalents/L.
Normality
most commonly used for H+ concentration
A 1 N solution of acid contains an [H+] equal to ____ mol/L.
1
In acid-base chemistry, the gram equivalent weight represents what?
The mass of acid that yields 1 mol of H+, or the mass of base that yields 1 mol of OH-
The law of ____________ ________________ states that any pure sample of a given compound will contain the same elements in an identical mass ratio.
constant composition
The ____________ formula gives the simplest whole-number ratio of elements in a compound.
empirical
The ________________ formula gives the exact number of atoms of each element in the compound and is a multiple of the empiral formula.
molecular
Ionic compounds, such as NaCl or CaCO3, will only have ____________ formulas.
empirical
The ____________ ________________ of an element (by mass) is the % of a specific compound that is made up of a given element.
percent composition
Given the percent composition of a compound, how do you find the e.f. and m.f.?
Empirical formula:
1. Assume sample is 100 g.
2. Convert % of each element to g.
3. Divide each value by respective molar mass to find mol.
4. Divide each value by smallest mol amount.
5. Multiply by integer value to get whole number
Molecular formula:
1. Divide given molar mass by formula weight of e.f.
A ________________ reaction has 2+ reactants forming one product.
combination
A ________________ reaction is the opposite of a combination reaction: a single reactant breaks down into 2+ products.
usually heat, radiation, electrolysis
decomposition
A ____________ reaction is a special type of reaction that involves fuel, usually a hydrocarbon, and an oxidant (normally oxygen)
combustion
What are the products of a combustion reaction?
CO2 and H2O
A ________-________________ reaction occurs when an atom or ion in a compound is replaced by an atom or ion of another element.
single-displacement
In ________-________________ reactions, also known as metathesis reactions, elements from 2 different compounds swap places with each other to form 2 new compounds.
double-displacement
____________ reactions are a specific type of double-displacement reaction in which an acid reacts with a base to produce a salt and usually water.
Neutralization
In most reactions, one reactant will be used up or consumed first. This is the ____________ ____________.
limiting reagent
For elements (usually metals) that can form more than 1 positive ion, the charge is indicated by a Roman numeral in parentheses following the element’s name. What is Fe2+ and Fe3+?
Iron (II)
Iron (III)
The ending -ous and -ic refer to ions with what?
What is Fe2+ and what is Fe3+?
-ous is less, -ic is more
Ferrous, ferric
Monatomic anions are named by dropping the ending of the name of the element and adding what ending? What is H-? O-?
-ide
Hydride, oxide
Many polyatomic anions contain oxygen and are thus called ____________. When an element forms 2 oxyanions, the name of the one with less oxygen ends in ____ and the one with more oxygen ends in ____.
oxyanions; -ite, -ate
In the extended series of oxyanions, prefixes are also used. ________ and ________ are prefixes used to indicates less and more oxygen, respectively.
What are the below?
ClO-
ClO2-
ClO3-
ClO4-
Hypo-, per-
Hypochlorite
Chlorite
Chlorate
Perchlorate
Polyatomic anions often gain 1+ H+ ions to form anions of lower charge. The resulting ions are named by adding “hydrogen” or “dihydrogen” to the front of the anion’s name. An older method uses the prefix “bi-“ to indicate the addition of a single H+.
What are the following?
HCO3-
HSO4-
H2PO4-
Hydrogen carbonate, bicarbonate
Hydrogen sulfate, bisulfate
Dihydrogen phosphate
What is NH4+?
ammonium
What is C2H3O2-?
acetate
What is CN-?
cyanide
What is MnO4-?
Permanganate
What is SCN-?
Thiocyanate
What is CrO42-?
Chromate
What is Cr2O72-?
dichromate
What is BO33-?
borate
What is the formula for ammonium?
NH4+
What is the formula for acetate?
C2H3O2-
What is the formula for cyanide?
CN-
What is the formula for permanganate?
MnO4-
What is the formula for thiocyanate?
SCN-
What is the formula for chromate?
CrO42-
What is the formula for dichromate?
Cr2O72-
What is the formula for borate?
BO33-
Solutes that enable solutions to carry currents are called ________________.
electrolytes
In ____________ solutions, however, the lattice arrangement is disrupted by the ion-dipole interactions between the ionic components and the water molecules. Thus the ionic solution can conduct electricity.
aqueous
A solute is considered a strong electrolyte if it ____________ completely into its constituent ions.
dissociates
