Chemistry - Ch 4 Flashcards
Aqueous solution
a solution in which water is the dissolving medium
Solution
homogeneous mixture of 2+ substances
Solvent
substance present in the greatest quantity in a solution
Solutes
other substances in the solution, said to be dissolved in the solvent
Electrolyte
a substance whose aqueous solutions contain ions (ex. NaCl)
Nonelectrolyte
a substance that does not form ions in solution (ex. C12H22O11)
Dissociates
an ionic solid breaking up into its component ions as it dissolves
Solvation
process that helps stabilize the ions in solution and prevents cations and ions from recombining; water molecules surround the ions as an ionic compound dissolves (ions are solvated)
Strong electrolytes
solutes that exist in solution completely or nearly completely as ions (all soluble ionic compounds, like NaCl, and a few molecular compounds, like H20 are strong electrolytes)
Weak electrolytes
solutes that exist in solution mostly in the form of molecules with only a small fraction in the form of ions
Chemical equilibrium
relative numbers of each type of ion or molecule in the reaction are constant over time
Soluble ionic compounds are ___ electrolytes
strong
Precipitation reactions
reactions that result in the formation of an insoluble product
precipitate
insoluble solid formed by a reaction in solution
Solubility
amount of the substance that can be dissolved in a given quantity of solvent at the given temperature
Insoluble
any substance with a solubility less than .01 mol/L
all common ionic compounds of the ______ and of the ____ ion are soluble in water
alkali metal ions; ammonium
Exchange reactions (metathesis reactions)
reactions in which positive ions and negative ions appear to exchange partners (AX + BY –> AY + BX), like precipitation reactions
Molecular equation
equation showing the complete chemical formulas of the reactants and the products; shows the chemical formulas of reactants/products without indicating their ionic character
Complete ionic equation
equation written with all soluble strong electrolytes shown as ions
Spectator ions
ions that appear in identical forms among both the reactants and the products of a complete ionic equation (play no direct role in the reaction)
Net ionic equation
when spectator ions are omitted from the equation (cancel like algebraic quantities)
If every ion in a complete ionic equation is a spectator, then __ _______ ________
No reaction occurs
Acids
substances that ionize in aqueous solutions to form hydrogen ions, thereby increasing the concentration of H+ (aq) ions; AKA “proton donors”
Monoprotic acids
HCl & HNO3; yield one H+ per molecule of acid
Diprotic acid
Yields 2 H+ per molecule of acid (ex. sulfuric acid, H2SO4)
Bases
substances that accept (react with) H+ ions; produce OH- when they dissolve in water (ex. NaOH, KOH, Ca(OH)2; NH3)
Strong acids, strong bases
acids and bases that are strong electrolytes (completely ionized in solution)
Weak acids, weak bases
weak electrolytes (partly ionized)
Hydrochloric acid
HCl
Hydrobromic acid
HBr
Hydroiodic acid
HI
Chloric acid
HClO3
Perchloric acid
HClO4
Nitric acid
HNO3
Sulfuric acid
H2SO4
Group 1A Metal hydroxides (strong bases)
LiOH, NaOH, KOH, RbOH, CsOH
Heavy group 2A metal hydroxides
Ca(OH)2, Sr(OH)2, Ba(OH)2
Neutralization reaction
when a solution of an acid and a solution of a base are mixed
Salt
any ionic compound whose cation comes from a base and whose anion comes from an acid; a neutralization reaction between an acid and a metal hydroxide produces water and a salt
Antacids
substances that remove excess acid
Acid inhibitors
substances that decrease the production of acid
Oxidation-reduction (redox) reactions
electrons are transferred between reactants
Corrosion
conversion of a metal into a metal compound by a reaction between the metal and some substance in its environment
Oxidation
loss of electrons by a substance
Reduction
when an atom, ion, or molecule has become more negatively charged (gained electrons)
Oxidation number
actual charge for a monatomic ion
For an atom in its elemental form, the oxidation number is always _____
zero
For any monatomic ion, the oxidation number equals ____________
the charge on the ion
Nonmetals usually have _____ oxidation numbers
negative
The sum of the oxidation numbers of all atoms in a neutral compound is ____
zero
Displacement reactions
the ion in solution is displaced or replaced through oxidation of an element
Activity series
a list of metals arranged in order of decreasing ease of oxidation; any metal on the list can be oxidized by the ions of elements below it
Active metals
alkali metals, alkaline earth metals are most easily oxidized (they react most readily to form compounds)
Noble metals
transition metals from groups 8B & 1B very stable and form compounds less readily
Concentration
the amount of a solute dissolved in a given quantity of solvent or quantity of solution
Aqua regia
royal water; gold dissolved in a 3:1 mixture of concentrated hydrochloric and nitric acids
Molarity (M)
concentration of a solution as the number of moles of solute in a liter of solution; moles solute/volume of solution in liters
Stock solutions
solutions that are used routinely in the lab, often purchased or prepared in concentrated form
Dilution
solutions of lower concentrations can be obtained by adding water to stock solution
hyponatremia
a condition in which the concentration of sodium ion in the blood is too low due to excess water consumption
titration
combining a sample of the solution with a reagent solution of known concentration (standard solution); used to determine the concentration of a particular solute in a solution; can be conducted using acid-base, precipitation, or oxidation-reduction reactions
Standard solution
reagent solution of known concentration
Equivalence point (of the titration)
the point at which stoichiometrically equivalent quantities are brought together
Acid-base indicators
dyes used in acid-base titrations to determine when the equivalence point of the titration has been reached
