CHEM 134 test 3 summer 2
What is the common-ion effect - answer whenever a weak electrolyte and a strong
electrolyte containing a common ion are together in solution, the weak electrolyte
ionizes less than it would if it were alone in the solution
what is a buffered solution - answer solutions that contain a weak conjugate acid-base
pair, that resist drastic changes in pH when small amounts of strong acid or strong base
are added to them
what is the buffer capacity - answer the amount of acid or base the buffer can neutralize
before the pH begins to change to an appreciable degree
what is the pH range of a buffer - answer the range over which the buffer acts effectively
what is a pH titration curve - answer a graph of the pH as a function of the volume of
titrant added
what is the initial pH - answerthe pH of the solution before the addition of any base,
determined by the initial concentration of the strong acid
what is between the initial pH and equivalence point - answerThe pH before the
equivalence point
what is the equivalence point - answeran equal amount of moles of acid and base have
reacted
what is the after eqivalance point - answerthe pH of the solution after the equivalence
point is determined
Why is pH at the equivalence point larger than 7 when you titrate a weak acid with a
strong base? - answerThe conjugate base that is formed at the equivalence point reacts
with water.
You have an aqueous solution of chromium(III) nitrate that you titrate with an aqueous
solution of sodium hydroxide. After a certain amount of titrant has been added, you
observe a precipitate forming. You add more sodium hydroxide solution and the
precipitate dissolves, leaving a solution again. What has happened? - answerThe
precipitate was chromium hydroxide, which then reacted with more hydroxide to
produce a soluble complex ion, Cr(OH)4−
what is an oxidizing agent - answerthe substance that makes it possible for another
substance to be oxidized
What is the common-ion effect - answer whenever a weak electrolyte and a strong
electrolyte containing a common ion are together in solution, the weak electrolyte
ionizes less than it would if it were alone in the solution
what is a buffered solution - answer solutions that contain a weak conjugate acid-base
pair, that resist drastic changes in pH when small amounts of strong acid or strong base
are added to them
what is the buffer capacity - answer the amount of acid or base the buffer can neutralize
before the pH begins to change to an appreciable degree
what is the pH range of a buffer - answer the range over which the buffer acts effectively
what is a pH titration curve - answer a graph of the pH as a function of the volume of
titrant added
what is the initial pH - answerthe pH of the solution before the addition of any base,
determined by the initial concentration of the strong acid
what is between the initial pH and equivalence point - answerThe pH before the
equivalence point
what is the equivalence point - answeran equal amount of moles of acid and base have
reacted
what is the after eqivalance point - answerthe pH of the solution after the equivalence
point is determined
Why is pH at the equivalence point larger than 7 when you titrate a weak acid with a
strong base? - answerThe conjugate base that is formed at the equivalence point reacts
with water.
You have an aqueous solution of chromium(III) nitrate that you titrate with an aqueous
solution of sodium hydroxide. After a certain amount of titrant has been added, you
observe a precipitate forming. You add more sodium hydroxide solution and the
precipitate dissolves, leaving a solution again. What has happened? - answerThe
precipitate was chromium hydroxide, which then reacted with more hydroxide to
produce a soluble complex ion, Cr(OH)4−
what is an oxidizing agent - answerthe substance that makes it possible for another
substance to be oxidized
