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;
20 Cards in this Set
- Front
- Back
|
Acid
|
Aqueous acids have a pH of less than 7, and accepts OH ions readily
|
|
|
Base
|
a substance that can accept H ions or more generally, donate electron pairs
|
|
|
Arrhenius Acid
|
a substance that when added to water increases the concentration of H+ ions present
|
|
|
Arrhenius Base
|
a substance that when added to water increases the concentration of OH- ions present
|
|
|
Bronsted-Lowry Acid
|
any substance that can donate a hydrogen ion (proton)
|
|
|
Bronsted-Lowry Base
|
any substance that can accept a hydrogen ion (proton)
|
|
|
Dissociation of Water
|
the chemical reaction in which a proton is transferred from one water molecule to another, in pure water or an aqueous solution, to create the two ions, hydronium, H3O+ and hydroxide, OH−
|
|
|
Acid Dissociation Constant
|
a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid-base reactions:
HA <==> A− + H+ |
|
|
Kw =
|
[H+] [OH-] = 10^(-14)
|
|
|
pH =
|
-log [H+]
|
|
|
Neutralization
|
a chemical reaction where an acid and a base react to form a salt. Water is frequently, but not necessarily, produced as well. Neutralizations with Arrhenius acids and bases always produce water:
YOH + HX → XY + H2O |
|
|
Acid-Base Titration
|
the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid or base solution
|
|
|
Strong Acid
|
an acid that ionizes completely in an aqueous solution by losing one proton, according to the equation:
HA(aq) → H+(aq) + A−(aq) |
|
|
Strong Base
|
a basic chemical compound that is able to deprotonate very weak acids in an acid-base reaction
|
|
|
Weak Acid
|
an acid that dissociates incompletely. It does not release all of its hydrogens in a solution, donating only a partial amount of its protons to the solution
|
|
|
Weak Base
|
a chemical base that does not ionize fully in an aqueous solution. As Bronsted-Lowry bases are proton acceptors, a weak base may also be defined as a chemical base in which protonation is incomplete. This results in a relatively low pH level compared to strong bases
|
|
|
Equivalence Point
|
the smallest amount of titrant that is sufficient to fully neutralize or react with the analyte. In some cases there are multiple equivalence points which are multiples of the first equivalent point
|
|
|
pH Indicator
|
a halochromic chemical compound that is added in small amounts to a solution so that the pH (acidity or basicity) of the solution can be determined visually. Hence a pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+) in the Arrhenius model
|
|
|
How do acid-base indicators work?
|
- Indicator changes color depending on how acidic or basic the substance is
- The dye on the litmus paper turns color based on its chemical structure when more H+ (acidic) ions are present or more OH- (basic) ions are present - Ph indicators are organic dyes that absorb light in the visible range - In order to get an organic substance to absorb in the visible range, it must have electrons that can vibrate freely over relatively long distances within the molecule - if there is a nitrogen atom that can accept a proton into its unbound electron group, then this small change will alter the resonant frequencies of the entire chain of double bonds, resulting in a slightly different absorbtion profile, and thus a different color - Base is the opposite, the proton is pulled off the molecule |
|
|
Why does it take several ml of .1M NaOH to change the pH of 10ml of .1M HCl solution from 1 to 2 and only one drop to change the pH from 6-7?
|
Due to the exponents in the pH scale, there is a greater overall difference in the number of H+ ions between 1 & 2 vs. 6 & 7. This means that less OH- ions would have to be added to the pH6 solution to bring it to pH7 than from pH1 to pH2
|
