Ch 9 Acid Base Buffers

Question 1

What is an Acid?

Answer 1

Substance that yields H+ when dissolved in Water. Simplified: A proton, H+, donor.

Question 2

An acid that donates one proton is termed?

Answer 2

Monoprotic

Question 3

An acid that donates two protons is termed?

Answer 3

Diprotic

Question 4

An acid that donoates three protons is termed?

Answer 4

Triprotic

Question 5

How do strong acids behave in water?

Answer 5

Fully dissociate, one-directional rxn, into hydronium ion (H3O+) and conjugate base (reactant minus a H+)

Question 6

How do weak acids behave in water?

Answer 6

Do NOT fully dissociate - create an equilibrium rxn.

Question 7

What is the relationship between pH and [H+] concentration?

Answer 7

inverse relationship. As pH goes up, [H+] goes down.
As pH goes down, [H+] goes up.

Question 8

The larger the [H+] the more ____ the solution

Answer 8

Acidic

Question 9

What is a Base?

Answer 9

A base is a proton, H+, Acceptor.

Question 10

Concentration of Base is measured by?

Answer 10

[OH-]

Question 11

As [OH-] goes up, what is happening to the solution?

Answer 11

More alkaline aka Basic Bitch

Question 12

what is the relationship between,
pOH and [OH-]

Answer 12

Inversely proportion. As [OH-] increases, pOH decreases.

Question 13

What is the relationship between pH and pOH

Answer 13

Low pH = High pOH
High pH = Low pOH

Question 14

13 on the pOH scale means the solution is basic or acidic?

Answer 14

ACIDIC

Question 15

2 on the pOH scale means the solution is basic or acidic?

Answer 15

BASIC

Question 16

As [OH-] goes up, what happens to pOH, pH, and [H+]?

Answer 16

pOH: goes down, a smaller number which means more basic

pH: goes up, bugger number, which means more basic

Question 17

pH + pOH always equals?

Answer 17

14

Question 18

An acid, once losing/donating its proton, becomes what on the product side?

Answer 18

Conjugate Base (of the acid)

Question 19

A base, once gaining/accepting a proton, becomes what on the product side?

Answer 19

Conjugate Acid (of the base)

Question 20

what is the pH equation?

Answer 20

pH = -log^[H+]

Question 21

What is the pH of a solution with a [H+] concentration of 1x10^-7?

Answer 21

7. Just take the absolute value of the exponent!

Question 22

What is the difference in [H+] of a pH of 6 compared to 8?

Answer 22

pH of 6 has 100x more H+

Each 1 change in pH is equal to 10x the change in [H+]

Question 23

Which is more acidic:
[H+] = 1x10^-5
[H+] = 1 x 10^-7

Answer 23

1x10^-5 because the exponent is 5, this is equal to the pH. 5 is less than 7, meaning it is more acidic on the pH scale.

Question 24

What is an amphoteric substance?

Answer 24

It can act as an acid or base, depending on the situation. Water is the primary example/

Question 25

Stronger or weaker have a higher Ka

Answer 25

Stronger Acids

Question 26

What is Kw?

Answer 26

Equilibrium constant for water. 1 x 10^-14

Question 27

Which rxn would give you relatively more product? A strong acid or weak acid?

Answer 27

Strong because it will not reverse back into the reactant

Question 28

Which has a larger Ka, strong or weak acids? Why?

Answer 28

Strong Acids have larger Ka. Because Ka= [product] / [reactant] , strong acids fully dissociate, there will be more product.

Question 29

equation for pKa

Answer 29

pKa = -logKa

Question 30

What are 5 strong acids

Answer 30

H2SO4, HI, HBr, HCL, HNO3

Question 31

What does Ka represent?

Answer 31

The strength of the acid, meaning how likely/much the acid wants to donate/loss its proton(s).

Question 32

When reviewing two weak acids, how do you determine which one is stronger?

Answer 32

Look at Ka. Stronger weak acid will have the large Ka.

Question 33

For polyprotic acids, which proton is donated more quickly/strongly?

Answer 33

The first proton donated. Review triprotic phosphoric acid.

Question 34

Regarding relationships between an acid and its conjugate base. The stronger the acid, the _______ its conjugate base.

Answer 34

Weaker

Question 35

Regarding relationships between a base and its conjugate acid. The stronger the base, the _______ its conjugate acid.

Answer 35

weaker

Question 36

What is the relationship between Ka and Pka?

Answer 36

Inverse. Higher Ka , lower pKa (same as base, Kb and pKb)

Question 37

pKa +pKb =

Answer 37

14

Question 38

if given a concentration, M, of a strong acid what is your concentration of the conjugate acid?

Answer 38

Same concentration of reactant strong acid

Question 39

if given a concentration, M, of a strong base what is your concentration of the conjugate base?

Answer 39

Same concentration of reactant strong base

Question 40

If your Ka or Kb value is high, (greater than 10^3) what direction will your reaction favor?

Answer 40

Product conc > reactant conc. So, a forward reaction is favored. Equilibrium lies to the right.

Question 41

If your Ka or Kb value is low (less than 10^-3), what direction will your reaction favor?

Answer 41

Reactant conc > product conc. So, a reverse reaction is favored. equilibrium lies to the left

Question 42

If your K value is about 1, what direction will your reaction favor?

Answer 42

Neither direction is favored. The reaction proceeds halfway. Conc of reactants ~ Conc of products

Question 43

What are some strong bases?

Answer 43

LiOH, KOH, NaOH, Ba(OH)2

Question 44

Why isn't Mg(OH)2 a strong base?

Answer 44

its insoluble

Question 45

The stronger the acid, the ______ its conjugate base.

Answer 45

Weaker. The conjugate base is "weak" if it is less likely to accept the proton it donated. Such is the case for a strong acid-conjugate base pair.

Question 46

The stronger the base, the _____ its conjugate acid.

Answer 46

Weaker. The OH- is less likely to donate the hydrogen it accepted.

Question 47

Does the conjugate base of a weak acid have base strength or not?

Answer 47

Does. It is capable of accepting the proton it initially donated, reversing the reaction.

Question 48

The reaction equilibirum always favors the formation of a?

Answer 48

weaker acid

Question 49

A change in 1 unit pH is equal to a ___ fold change in H+

Answer 49

10x

Question 50

pKw = ?

Answer 50

14 -log(Kw)

Question 51

pKa + pKb = ?

Answer 51

14

Question 52

IMPORTANT CONCEPT What is pKa relative to pH?

Answer 52

pKa is the pH at which 50% of the compound in solution is ionized and 50% of the compound is unionized. AKA: half acid, half conjugate base

Question 53

Why is NaCl neutral pH when dissolved in water?

Answer 53

Fully dissociates but does not react with water. Because water is neutral pH, and NaCl does not react, the pH of solution remains neutral.

Question 54

An Alpha plot demonstrates the ratio of?

Answer 54

The % ratio of ACID to Conjugate Base.