Aqueous equilibria

Question 1

Common Ion Effect

Answer 1

Shift in the position of equilibrium when you add something already involved in that equilibrium

Question 2

Chataliers principle

Answer 2

When something in equilibrium is changed, something else will try to counterbalance it. (seesaw)

Question 3

Buffers

Answer 3

Solutions that RESIST changes in pH when limited amounts of acid or base are added (maintains pH)

Question 4

WHat does a good buffer contain

Answer 4

conjugate acid and base in similar amounts

Question 5

Source of protons in a buffer is to? where does it get added?

Answer 5

Neutralize incoming bases

OH- into the reactants side

Question 6

Sink of protons in a buffer is to? Where does it get added?

Answer 6

neutralize incoming acids

H30 into the products side

Question 7

Henderson hasselbalch equation

Answer 7

pH = pKa +log([base(A) ]/[acid HA])

Question 8

What does Henderson hasselbalch equation highlight

Answer 8

the pH of a buffer solution has a value close to the pKa of the weak acid

Question 9

Buffer capacity: the ______ ______ of acid or base which the buffer can handle without significant _______ in pH

Answer 9

Molar amount

Changes

Question 10

For buffers: large shifts in the acid or base concentration =

Answer 10

small changes in pH

Question 11

Step 1 of Two Step approach for buffers:

Answer 11

Step 1: Find major species that remain after any strong acids or bases act (assume completion)

Question 12

Step 2 of Two Step approach for buffers:

Answer 12

Step 2: Determine the concentration of minor species that the major species generate.

Question 13

If have both acid and conjugate base in step 2 –> ______ –> H-H

Answer 13

buffer

Question 14

If only weak acid/base in step 2,

Answer 14

Acid/base dissociation –> ice table

Question 15

If have either H30+ or OH- directly remaining in step 2 from step 1,

Answer 15

Done

Question 16

Titration is a procedure for

Answer 16

determining the concentration of a solution by reacting it with another substance with a known concentration

Question 17

Titrations involving only strong acids or bases are

Answer 17

straightforward

Question 18

Titrations involving weak acids or bases are _________ by the ___________ of salts

Answer 18

complicated

dissociation

Question 19

Equivalence point

Answer 19

The point at which stoichiometrically equivalent quantities of acid and base have been mixed together

Question 20

At the equivalence point, what is happening?

Answer 20

Moles of base = moles of acid

(perfect neutralization)

Question 21

Which one has a higher equivalence point pH?

Weak acid-strong base titration

Strong acid-strong base titration

Answer 21

Weak acid-strong base titration

Question 22

pH in WEAK ACID/STRONG BASE TITRATIONS: “A” on graph (before addition of NaOH)

Answer 22

Ka = [H30+][A-] / [HA]

-log[H30] to find pH

Question 23

pH at “B”: before the equivalence point (Buffer region) (addition of something u use hen law)

Answer 23

pH = pKa + log [A-]/[HA]

NOTE!! when [HA]=[A-], pH = pKa

Question 24

finding pH at “C”: at the equivalence point

Answer 24

All of the HA has been converted to A, solution is basic, so use ice table and find KB

Question 25

finding pH at “D”: after equivalence point

Answer 25

there will be excess [OH] so u just convert that to pH

Question 26

Acid-base indicator

Answer 26

something that changes colour in specific pH range

Question 27

Why does acid-base indicator change colour depending on pH

Answer 27

They are weak acids and have different colours in their acid and conjugate base forms

Question 28

A titration graph going UP, the signs are A, B, C, and D. How to determine each?

Answer 28

A: weak ACID equilibrium
B: Buffer
C: equilibrium point (BASIC)
D: Leftover strong BASE

Question 29

A titration graph going DOWN, the signs are A’, B’, C’, and D’. How to determine each?

Answer 29

A’: weak BASE equilibrium
B’: Buffer
C’: Equilibrium point (ACIDIC)
D’: Leftover Strong ACID

Question 30

Solubility is

Answer 30

The amount of solute that dissolves in a given amount of solvent (mol/L)

Question 31

Chemical equation representing solubility

Answer 31

Mm Xx (s) <–> mMⁿ⁺ (aq) + xXʸ⁻ (aq)

Question 32

Solubility product is represented as Ksp, whats the formula?

Answer 32

Ksp = [Mⁿ⁺]ᵐ [Xʸ⁻]ˣ

Question 33

Solubility product, Ksp is a measure of

Answer 33

how much of an ionic compound has dissolved at equilibrium

Question 34

Precipitation of ionic compounds chemical equation

Answer 34

Its similar to solubility chemical equation just diff values:

AB (s) <—-> A+ (aq) + B- (aq)

Question 35

Qsp’s concentration formula

Answer 35

TIME!!!

Qsp = [A+]ₜ [B-]ₜ

Question 36

Ksp’s uses _____ instead of t

Answer 36

eq

Question 37

In solubility equilibriums, you can tell the shift direction if something is added by

Answer 37

common ion: shift opposite of where ion is (solubility decrease)

substance that reacts with one of the ions: Shift towards the side without that ion (solubility increase)

Question 38

practical buffer range

Answer 38

pKa +- 1

Question 39

What species are in the buffer region of a weak acid–strong base titration?

Answer 39

comparable amounts of weak acid and its conjugate base

Question 40

What species in the buffer region of a weak base–strong acid titration?

Answer 40

Predominant amounts of weak base and the conjugate acid

Question 41

for solving, strong base you

Answer 41

make one ice table and get poh out of that concentration

Question 42

for solving, weak base you

Answer 42

make one ice able and get that concentration, then u use that concentration and make another ice table to find the concentration for H30 or oH.

Question 43

DEPENDS IF THERES OH LEFT BRUHHH