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chem 2 chapter 15
acids and bases
Question | Answer |
---|---|
Acids react with bases to form what? | salt and water |
Conjugate base | the conjugate base of a bronsted acid is the species that remains when one proton has been removed from the acid. |
Conjugate acid | results from the addition of a proton to a bronsted base |
every bronsted acid and base has a what? | conjugate acid- base pair |
Arrhenius acid is a substance that produces what? | a H+ in water |
Arrhenius base is a substance that produces what? | OH- in water |
A bronsted acid is | a proton donor |
A bronsted base is | a proton acceptor |
auto ionization of water | water breaks down bu itself to produce H3O+ OH |
the ion product constant (Kw) | is the product of the molar concentrations of H+ and OH- ions at a particular temperature. |
Kw= | [H+][OH-]=1.0 X 10^14 |
[H+]=[OH-] | neutral [H+]=1.0x10^-7 ph=7 |
[H+]>[OH-] | acidic [H+]>1.0x10^-7 ph<7 |
[H+]<[OH-] | basic [H+]<1.0x10^-7 ph>7 |
ph | the negative logathrium of the hydrogen ion concentration in mol/L |
pOH = | -log[OH-] |
[H+][OH-]=kw= | 1.0x10^-14 |
-loh[H+]-[OH-]= | 14.00 |
ph+pOH = | 14.00 |
strong electrolyte | 100% dissociation |
weak electrolyte | not completely dissociated |
strong acids are | strong electrolytes that are assumed to ionize completely in water |
weak acids are | weak electrolytes that only ionize in water to a limited extent in water |
strong bases are | strong electrolytes that completely ionize in water |
weak bases are | weak electrolytes |
conjugate acid base pairs | -the conjugate base of a strong acid has no measurable strength. (weak conjugate base) -H30+ is the strongest acid that can exist in an aqueous solution -the OH- ion is the strongest base that can exis in aqueous solution. |
Ka Acid ionization constant | equilibrium constant for the ionization of an acid. -the larger the Ka the stronger the acid -if we know the ph of a weak acid solution and its initial concentration, we can determine its Ka |
Ka= | [H+][A-]/[HA] the acid ionization constant |
-log[H] gives you | the pOH, 14-pOH=pH |
If Ka/Kb= 1.0x10^-4 | first calculate the % of ionization not correcting for dissociation |
If Ka/Kb value is larger then 1/0x10^-4 | must use quadratic equation |
When is it ok to use the approximation? | when x is less then 5% of the value from which it was subtracted |
Solving weak acid ionization problems | 1. identify the major species that can affect the ph. 2. use ICE 3. Write Ka in terms of equilibrium concentrations. Solve for x by the approximation method. 4. Calculate concentrations of all species and/or ph of the solution |
percent ionization= | (ionized concentration at equilibrium/initial concentration of acid)x 100 |
[HA]0 | initial concentration |
KaKb= | Kw |
How can you tell how strong a bond is? | form the electronegativity |
oxoacids | 1.different central atoms that are from the same group and that have the same oxidation number. 2. oxoacids having the same central atom but different numbers of attached groups. |
Acid strength increases as the oxidation number ___? | increases |
Neutral solutions | salts containing an alkali metal or alkaline earth metal ion and the conjugate base of a strong acid |
Basic solutions | salts derived from a strong base and a weak acid |
Acid solutions | salts derived from a strong acid and a weak base |
solutions in which both cation and anion hydrolyze: | 1. Kb for the anion > ka for the cation, solution will be basic 2. Kb for the anion < ka for the cation, solution will be acidic 3. kb for the anion = ka for the cation, solution will be neutral |
A lewis acid | accepts a pair of electrons |
a lewis base | can donate a pair of electrons |