reactions in aqueous solutions Flashcards
what is a solute?
the gas (or solid) in a solution of gases (or solids) or the component in the smaller amount
what is a solvent?
the liquid in the case of a solution of gases or solids, or the component present in the larger amount
what is concentration?
the amount of solute dissolved in a solution
what is the equation for Molarity (M)?
Molarity (M)= moles of solute/liters of solution
what is dilution?
reducing the concentration of chemical
what happens to the number of moles and the molarity of a solution when it is diluted?
-the number of moles stays the same
-the molarity is decreased
what is the equation for dilution?
M1V1=M2V2
what are electrolytes?
substance that dissolves in water to give an electrically conducting solution
what is a nonelectrolyte?
substance that dissolves in water to give a non-conducting or very poor conducting solution
what is a strong electrolyte?
exists in a solution almost entirely as ions; separates completely into ions when dissolved
what is a weak electrolyte?
gives a relatively small percentage of ions; doesn’t completely separate into ions
what are the three types of chemical reactions?
-acid-base reactions
-precipitation reaction
-oxidation-reudction reaction
what is an acid-base reaction?
reactions that involve the transfer of a proton (H+) between reactants
what is a precipitation reaction?
solid ionic substance forms from the mixture of two solutions of ionic substances
what is an oxidation-reduction reaction?
reactions that include the transfer of electrons between reactants
what is an Arrhenius acid?
substance that produces hydrogen ions, H+, when it dissolves in water
what is an Arrhenius base?
substance that produces hydroxide ions, OH-, when it dissolves in water
what is a Brønsted-Lowry acid?
the molecule or ion that donates a proton to another molecule or ion in a proton-transfer reaction
what is a Brønsted-Lowry base?
molecule or ion that accepts a proton from another molecule or ion in a proton-transfer reaction
what is a strong acid?
acid that ionizes completely in water. Present entirely of ions, strong electrolyte
what are the strong acids (6)?
-HNO3
-HCl
-H2SO4
-HBr
-HClO4
-HI
what is a weak acid?
acid that only partly ionizes in water. Present primarily as molecules and partly as ions; weak electrolyte
-if an acid is not strong, it is weak
what is a strong base?
base that ionizes completely in water. Present entirely as ions; strong electrolyte
what are the strong bases (6)?
-LiOH
-Ca(OH)2
-NaOH
-Sr(OH)2
-KOH
-Ba(OH)2
what is a weak base? which bases are often weak?
-base that is only partly ionized in water. Present primarily as molecules and partly as ions; weak electrolyte
-nitrogen bases like NH3
what is an acid-base titration?
procedure for determining the amount of acid (or base) in a solution by determining the volume of base (or acid) od known concentration that will completely react with it
what is the equivalence point?
point in a titration when a stoichiometric amount of reactant has been added
what is a molecular equation?
chemical equation in which the reactants and products are written as if they may exist in the solution as ions (includes states)
what are ionic equations?
chemical equations in which strong electrolytes are written in molecular form
what is a net ionic equation?
chemical equation in which spectator ions are omitted. Shows the reaction that actually occurs in the solution
what is a precipitate?
insoluble solid compound formed during a chemical reaction in a solution
what is the basic formula for a precipitation reaction?
AX+BY –> AZ+BX
what is an oxidation number?
measure of the number of electrons an atom has in a compound verses the number of valence electrons
what is the rule for the oxidation number of elements?
if it’s neutral, its 0
what is the rule for the oxidation number of monatomic ions?
the charge on the ion
what is the rule for the oxidation number of oxygen?
-2 in most compounds (exception is 0 in H2O2 and other peroxides, where the oxidation number is -1)
what is the rule for the oxidation number of hydrogen?
+1 in most compounds (-1 in binary compounds with a metal such as CaH2)
what is the rule for the oxidation number of compounds and ions?
sum of the oxidation numbers of atoms in a compound is zero. The sum of oxidation numbers of atoms in a polyatomic ion equals the charge on the ion
what is a half-reaction?
one of the two parts of a redox reaction, one part of which involves a loss of electrons and the other part of which involves a gain of electrons
what is oxidation?
half-reaction in which there is a loss of electrons by a species
-increase in oxidation number
what is reduction?
half-reaction in which there is a gain of electrons by a species
-decrease in oxidation number
what is an oxidizing agent?
species that oxidizes another species
-it is reduced
what is a reducing agent?
species that reduces another species
-it is oxidized
