Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
55 Cards in this Set
- Front
- Back
|
T/F: All acids contain hyrdogen but not all hydrogen-containing substances are acids.
|
True
|
|
|
Substances that produce H+ ions in water are...
|
Acids
|
|
|
Substances that produce OH- ions in water are...
|
Bases
|
|
|
Hydrogen Chloride is a gas, but when dissolved in water, it is an acid known as...
|
Hydrochloric Acid (This is an ARRHENIUS acid, and NaOH is an ARRHENIUS base)
|
|
|
T/F: The Arrhenius concept is helpful, but is limited to aqueous solutions.
|
True
|
|
|
The Bronsted-Lowry definition of acids is based on the fact that...
|
Acid-base reactions involve the transfer of H+ ions from one substance to another.
|
|
|
T/F: An H+ ion is simply a proton with no surrounding valence electron.
|
True
|
|
|
What does the interaction of an H+ ion (proton) produce with water? What is the molecular formula for this?
|
A hydronium ion; H3O+ (aq)
|
|
|
T/F: The H+ ion and the H3O+ are generally the same thing and can be used interchangably because an H+ ion rarely exists by itself, however the H3O ion more closely represents reality and is often used on the AP test.
|
True
|
|
|
T/F: The polar H2O molecuule promotes the ionization of acids in water solution by accepting a proton (H+) to form H3O+.
|
True
|
|
|
(Bronsted and Lowry proposed definitions of acids and bases in terms of their proton transferring abilities) A substance that DONATES a proton to another substance is an _. A substance that accepts a proton is a _.
|
Acid (HCl is thus a Bronsted-Lowry acid); base (H2O is a B-L base!)
|
|
|
T/F: An acid and a base always work together to transfer a proton (duh).
|
True
|
|
|
A subtance (such as water) that is capable of acting as either an acid or a base is called...
|
Amphiprotic
|
|
|
An acid and a base (such as HX and X- which are the same substance with only a difference of a proton (H+) on opposite sides of an equilibrium equation) that differ only in the presence or absence of a proton are called a...
|
Conjugate acid-base pair
|
|
|
T/F: Every acid has a conjugate base, and vice versa.
|
True
|
|
|
What is the conjugate acid of H2O? Of HX?
|
H3O+, X-
|
|
|
T/F: The stronger an acid, the weaker its conjugate base; the stronger a base, the weaker is its conjugate acid
|
True
|
|
|
What is the conjugate BASE of H2O (because it's amphiprotic it has both conjugate acids and bases)?
|
OH-
|
|
|
T/F: A strong acid completely transfers its protons to water, leaving no undissociated molecules in solution. It's conjugate base is negligible.
|
True
|
|
|
The conjugate base of a weak acid is a...
|
Weak base
|
|
|
What happens when a strong acid is placed in water and what is this based on?
|
The H2O (the base) is much stronger than the Cl- conjugate base. So, after full dissociation of the strong acid, there is only H3O+ and Cl- truly left in the solution. Thus the equilibrium lies to the right.
|
|
|
When will equilibrium in a strongacid and base reaction lie to the left?
|
When the X- ion is a stronger base than H2O, thus when HX is a weak acid.
|
|
|
T/F: In every acid-base reaction the position of the equilibrium favors transfer of the proton from the stronger acid to the stronger base to form the weaker acid and the weaker base.
|
True
|
|
|
When one water molecule donates a proton to another water molecule, this is called...
|
Autoionization
|
|
|
Write the equation of Kw and the ultimate value of Kw at 25C. (There are two equations used interchangeably)
|
Kw = [H3O+][OH-] = [H+][OH-] = 1.0 X 10^-14
|
|
|
When [H+] = [OH-], what is the solution said to be?
|
Neutral
|
|
|
What is the equation used to calculate pH from the concentration of H+ ions?
|
pH = -log([H+]) OR pH = -log([H3O+)]
|
|
|
T/F:
-log[H+] + -log[OH-] = -log(Kw) pH + pOH = 14.00 |
True
|
|
|
Why is calculating the pH of a solution of water and a strong acid like HNO3 easy?
|
Because, when given the initial [HNO3], the concentration of H+ is equivalent to the initial concentration because of full dissociation, and you just take the negative log of that. (Same goes for fully-dissociating strong bases)
|
|
|
What does Ka denote?
|
The acid-dissociation constant
|
|
|
T/F: The larger the value of Ka, the stronger the acid.
|
True, because that means the products are bigger over the reactants, where the products are the ionized side.
|
|
|
What are the two equations for percent ionization?
|
percent ionization = (concentration ionized)/(original concentration) x 100
OR percent ionization = [H+]equilibrium/[HA] initial |
|
|
T/F: The Hydrogen in a seemingly organic compound that ACTUALLY dissociates is always the one connected to the oxygen.
|
True
|
|
|
When should you and should you NOT assume that the value of x is negligible?
|
When x is more than about 5% of the initial value.
|
|
|
T/F: The percent ionization of a weak acid decreases as the concentration increases because more and more of the weak acid is added while only a small percent of it continues to dissociate.
|
True
|
|
|
Acids that have more than one ionizable H atom are called...
|
Polyprotic acids
|
|
|
T/F: It is always easier to remove the first proton from a polyprotic acid than to remove the second, so Ka2 will be much smaller than Ka1.
|
True
|
|
|
T/F: When the Ka1 and Ka2 values of a polyprotic acid differ by more than 10^3, you can just solve for Ka1.
|
True
|
|
|
What is the most commonly encountered weak base?
|
Ammonia
|
|
|
The constant Kb is called the...
|
Base-dissociation constant
|
|
|
T/F: The constant Kb always refers to the equilibrium in which a base reacts with H2O to form the corresponding conjugate acid and OH-.
|
True
|
|
|
What is the first category of weak bases?
|
Amines, or compounds without a charge that usually have a Nitrogen with a nonbonding pair of electrons to which an extra H+ applies.
|
|
|
What is the second general category of weak bases?
|
Anions of weak acids, of course
|
|
|
T/F: In aqueous reactions, NaClO dissociates while Na+ acts as a spectator ion.
|
True
|
|
|
Describe the amazing, unique relationship of Ka and Kb.
|
Ka x Kb = Kw = 1.0 x 10^-14
|
|
|
T/F: So, the product of the acid-dissocation constant for an acid and the base-dissociation constant for its conjugate base equals the ion-product constant for water.
|
True (but ONLY applies to conjugate acid-base pairs) **The other equation is pKa + pKb = pKw = 14.00
|
|
|
How can you tell if a certain anion is a spectator ion in the reaction or not (i.e., if it produces any OH-s when reacting with water)?
|
If you find the conjugate acid of the anion, and it just so happens to be one of the strong acids, then its ability to form OH-s when mixed with water is negligible and it is a spectator ion.
|
|
|
T/F: The cations of arrhenius bases will not affect pH just as the anions of strong acids will not affect pH.
|
True
|
|
|
T/F: When a solution contains both the conjugate base of a weak acid and the conjugate acid of a weak base, the ion with the larger Ka or Kb will have the greater influence on the pH.
|
True
|
|
|
Cations like Al3+ that are not in groups 1A or 2A are...
|
Acidic (if they ARE group 1A or 2A, they have no affect on the reaction as spectator ions)
|
|
|
T/F: Acidity increases as the electronegativity of the element X in HX increases, as it does moving from left to right in a row.
|
True
|
|
|
Acids in which OH groups and possibly additional oxygen atoms are bound to a central atom are called...
|
Oxyacids
|
|
|
What is the rule for acidity with the general oxyacid compound Y-O-H?
|
As the electronegativity of Y increases, so will the acidity of the substance, because the O and Y will hold onto eachother more readily and the H+ will be more likely to give off.
|
|
|
T/F: The strength of an oxyacid will increase as additional electronegative atoms bond to the central atom Y.
|
True
|
|
|
Acids with a COOH group on the end are called...
|
Carboxylic acids
|
