Ch 4 - Chemical Quantities and Aqueous Reactions Flashcards
Stoichiometry
the numerical relationships between chemical amounts in a balanced chemical equation.
Allows us to predict the amounts of products that will form from a chemical reaction based on the amount of reactants that react.
limiting reactant
the reactant that limits the amount of product in a chemical reaction.
Reactant in excess
the reactant that does not limit the reaction and has some left over.
Theoretical Yield
the maximum amount of product that can be made in a chemical reaction based on the amount of the limiting reactant.
Actual Yield
the amount of product actually produced by a chemical reaction.
Percent Yield
actual yield/theoretical yield.
Solution
a homogeneous mixture of two substances
Solvent
the majority component in a solution
Solute
the minority component in a solution
Aqueous Solution
A solution where water acts as the solvent
Dilute Solution
a solution that contains a small amount of solute relative to the solvent
Concentrated Solution
a solution that contains a large amount of solute relative to the solvent
Molarity(M)
the amount of solute(in moles) divided by the volume of solution(in liters)
M = Amount of solute(in moles) / volume of solution(in L)
Stock Solution
Concentrated solution forms which can be diluted to desired concentrations
M1V1 = M2V2
V1 = (0.500 * 3.00) / 10.0 = 0.150 L
Electrolyte
Substances that dissolve in water to form solutions that conduct electricity
Strong Electrolyte
Substances that completely dissolve in water
Nonelectrolyte
Compounds who do not dissociate into ions when dissolved in water.
Do not conduct electricity
Strong Acid
An acid that completely ionizes in solution.
Weak Acid
An acid that does not completely ionize in water
Weak electrolyte
typically composed of weak acids.
Conduct electricity weakly
Soluble
a compound that can be dissolved in water
Insoluble
a compound that can not be dissolved in water
Soluble Rules:
Li^+, Na^+, K^+, and NH4^+
Always soluble. No exceptions.
Soluble Rules:
NO3^- and C2H3O2^-
Always soluble. No exceptions.
Soluble Rules:
Cl^-, Br^-, and I^-
Typically soluble.
Exceptions: Insoluble when paired with:
Ag^+, Hg^2+, or Pb^2+
Soluble Rules:
SO4^2-
Typically soluble.
Exceptions: Insoluble when paired with:
Sr^2+, Ba^2+, Pb^2+, Ag^+, or Ca^2+
Soluble Rules:
OH^- and S^2-
Typically insoluble.
Exceptions: Soluble when paired with:
Li^+, Na^+, K^+, or NH4^+
or
Ca^2+, Sr^2+, or Ba^2+
Soluble Rules:
CO3^2- and PO4^3-
Typically Insoluble.
Exceptions: Soluble when paired with:
Li^+, Na^+, K^+, or NH4^+
Precipitation Reaction
reactions in which a solid, a precipitate, forms when we mix two solutions
Precipitate
a solid formed from mixing two solutions.
Only insoluble compounds form precipitates.
Molecular Equation
an equation showing the complete neutral formulas for each compound in a reaction as if they existed as molecules.
Complete Ionic Equation
an equation which list all of the ions present as either reactants or products in a chemical reaction.
Spectator Ions
in a complete ionic equation the ions in solution that appear unchanged on both sides of the equation.
Net Ionic Equation
an equation that show only the species that actually changed during a reaction.
Spectator ions are left out of this equation.
Only the interesting stuff stays in the equation.
Acid-Base Reaction(Neutralization Reaction)
an aqueous reaction where and acid and a base react to neutralize each other while producing water and sometimes a weak electrolyte.
Gas-Evolution Reaction
a reaction in which a gas is formed resulting in bubbling
Many acid-base reactions are this.
Acid
substance that produces H^+ ions in aqueous solution
Base
substance that produces OH^- ions in aqueous solution
Arrhenius Definitions
Named after Svante Arrhenius. Defined Acids and Bases.
Hydronium Ion
H^+ is a bare proton and in solution they typically associate with H2O
H^+(aq) + H2O(l) -> H3O^+(aq)
H^+ or H3O^+ both mean a hydronium ion.
Polyprotic Acids
Example with a Diprotic Acid
an acid containing more than one ionizable proton and release them sequentially.
First it is strong(one way reaction)
H2SO4(aq) -> H^+(aq) + HSO4^-(aq)
Second it is weak(the reaction can go both ways)
HSO4^-(aq) -><- H^+(aq) + SO4^2-(aq)
Hydrochloric Acid
HCl
Hydrobromic Acid
HBr
Hydroiodic Acid
HI
Nitric Acid
HNO3
Sulfuric Acid
HSO4
Perchloric Acid
HCLO4
Acetic Acid
weak acid.
HC2H3O2
Hydroflouric Acid
Weak acid.
HF
Sodium Hydroxide
NaOH
Lithium Hydroxide
LiOH
Potassium Hydroxide
KOH
Calcium Hydroxide
Ca(OH)2
Barium Hydroxide
Ba(OH)2
Ammonia
Weak Base.
NH3
Salt
typically formed in an acid-base reaction. Stays dissolved in the solution but is an ionic compound.
Acid + Base ->
Water + salt
Titration
a substance in a solution of known concentration is reacted with another substance in a solution of unknown concentration. Used to determine concentration of unknown solution.
Equivalence Point
the point in the titration when the number of moles of OH^- added = the number of moles of H^+ initially in the solution.
Indicator
signals the equivalency point of a titration by using a dye whose color depends on the acidity or basicity of the solution.
Intermediate Product
an unstable and quickly decomposing product in a Gas-Evolution Reaction
Reactant Type:
Sulfides
Intermediate Product: None
Gas Evolved: H2S
Reactant Type:
Carbonates and bicarbonates
Intermediate Product: H2CO3
Gas Evolved: CO2
Reactant Type:
Sulfites and bisulfites
Intermediate Product: H2SO3
Gas Evolved: SO2
Reactant Type:
Ammonium
Intermediate Product: NH4OH
Gas Evolved: NH3
Oxidation-Reduction Reactions(redox reactions)
reactions in which electrons transfer from one reactant to the other.
Many involve a substance with oxygen.
Oxidation
the loss of an electron.
Reduction
the gain of electrons.
Oxidation State(number)
A theoretical number given to each atom based on the electron assignments.
Noted as “-1” instead of an ionic charge of “1-“
Oxidation State Rule 1
The Ox State of an atom in a free element is 0.
Cl2 = 0 ox state.
Oxidation State Rule 2
The Ox State of a monoatomic ion is equal to its charge.
Ca^2+ = +2 Ox State
Oxidation State Rule 3
the sum of the oxidation states of all atoms in:
- A neutral molecule or formula unit = 0
H20 = 2(H ox state) + 1(O ox state) = 0 - An ion is equal to the charge of the ion.
NO3^- = 1(N ox state) + 3(O ox state) = -1
Oxidation State Rule 4
In their compounds, metals have positive ox states
- Group 1A always have an ox state of +1
- Group 2A always have an ox state of +2
Oxidation State Rule 5
in their compounds nonmetals are assigned ox state as follows:
Flourine = -1 Hydrogen = +1 Oxygen = -2 Group 7A = -1 Group 6A = -2 Group 5A = -3
Oxidation
An increase in oxidation state
Reduction
A decrease in oxidation state
Oxidizing Agent
a substance that causes the oxidation of another substance
Reducing Agent
a substance that causes the reduction of another substance
The Only 7 Strong Acids
HCl - Hydrochloric Acid HBr - Hydrobromic Acid HI - Hydroiodic Acid HNO3 - Nitric Acid H2SO4 - Sulfuric Acid HClO3 - Chloric Acid HClO4 - Perchloric Acid
Strong Bases
Alkali Metals
Calcium
Strontium
Barium
