General Chemistry Chapter 10: Acids and Bases Flashcards Preview

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Flashcards in General Chemistry Chapter 10: Acids and Bases Deck (34)
1

Arrhenius acids

dissociate to produce an excess of hydrogen ions in solution

2

Arrhenius bases

dissociate to produce an excess of hydroxide ions in solution

3

Bronsted-lowry acids

are species that can donate hydrogen ions

4

Bronsted-lowry bases

species that can accept hydrogen ions.

5

Lewis acids

Electron pair acceptors

6

Lewis bases

Electron pair donors

7

Amphoteric species

those that can behave as an acid or base

8

Amphiprotic species

are amphoteric species that specifically can behave as a Bronsted-Lowry acid or Bronsted-Lowry base

9

What is the classic example of an amphoteric, amphiprotic species?

Water or conjugate species of polyvalent acids and bases

10

Water dissociation constant (Kw)

10^-14 at 298 K. It is only affected by changes in temperature.

11

pH and pOH

Can be calculated given the concentrations of H3O+ and OH- respectively . In aqueous solutions, pH + pOH = 14 at 298 K.

12

in solution, strong acids and bases

completely dissociate

13

In solution, weak acids and bases

do not completely dissociate in solution and have corresponding dissociation constants (Ka and Kb)

14

The conjugates of strong acids and bases have ___ conjugates

weak

15

Neutralization reactions form:

salts and sometimes water

16

Equivalent

one mole of the species of interest

17

Normality

concentration of acid or base equivalents in solution.

18

Polyvalent acids and bases

are those that can donate or accept multiple electrons. The normality of a solution containing a polyvalent species is the molarity of the acid or base times the number of protons it can donate or accept.

19

Titrations

Used to determine the concentration of a known reactant in solution.

20

Titrant

has a known concentration and is added slowly to the titrand to reach the equivalence point.

21

Titrand

has an unknown concentration, but a known volume

22

Half-equivalence point

midpoint of the buffering region in which half of the titrant has been protonated (or deprotonated); thus [HA] = [A-] and a buffer is formed.

23

Equivalence point

indicated by the steepest slope in a titration curve; it is reached when the number of acid equivalents in the original solution equals the number of base equivalents added; or vice versa.

24

Strong acid/strong base titrations have equivalence points at

pH=7

25

Weak acid/strong base titrations have equivalence points at

pH >7

26

Weak base/strong acid titrations have equivalence points at:

above or below 7, depending on the relative strength of the acid and base.

27

Indicators

are weak acids or bases that display different colors in their protonated and deprotonated forms

28

The indicator pH

should have a pKa close to the pH of the expected equivalence point

29

endpoint of a titration

is when the indicator reaches its final color

30

In polyvalent acid and base titrations

multiple buffering regions and equivalence points are observed

31

Buffering solutions

consist of a mixture of a weak acid and its conjugate salt or a weak base and its conjugate salt. They resist large fluctuations in pH.

32

Buffering capacity

refers to the ability of a buffer to resist changes in pH; minimal buffering capacity is seen within 1 pH point of the pKa of the acid in the buffering solution.

33

Henderson-Hasselbalch

quantifies the relationship between pH and pKa for weak acids and between pOH and pKb for weak bases.

34

When a solution is optimally buffered, pH = & pOH=

pH = pKa and pOH = pKb