chapter 2: Acid and bases

Question 1

HA is what

Answer 1

Bronsted acid

Question 2

A- is what

Answer 2

conjugate base of the acid

Question 3

H3O is what?

Answer 3

Conjugate acid of a base

Question 4

The negatively charged product acid base reaction is what?

Answer 4

the conjugate base

Question 5

The positively charged product of an acid-base reaction is what?

Answer 5

the conjugate acid

Question 6

the ammonium ion (NH4+) is what of ammonia (NH3)

Answer 6

NH4+ is the conjugate acid

Question 7

Lewis acid does what?

Answer 7

accepts an electron pair making it decrease in charge

Question 8

Lewis base does was?

Answer 8

Donates electron pair increasing in charge

Question 9

The equilibrium/dissociation constant is what?

Answer 9

A quantity that is a measure of the relative proton affinities of the A-/HA and H3O+/ H2O conjugate acid-base pairs

Question 10

pH =

in terms of [H+]

Answer 10

-log[H+]

Question 11

Kw =

Answer 11

[H+][OH-]

Question 12

Acids with lower pK are what?

Answer 12

Stronger acids

Question 13

Acids with larger dissociation constants are what?

Answer 13

Stronger acids

Question 14

Acids with a dissociation constant smaller than that of H3O+ are what?

Answer 14

weak acids (K<1)

Question 15

Strong acids have a dissociation constant larger than what?

Answer 15

H3O+ (K>1) so strong acids are almost completely ionized in aqueous solutions

Question 16

Solutions with [H+] = 10^7 M are what?

Answer 16

Neutral

Question 17

Solutions with [H+] > 10^-7 M are what?

Answer 17

acidic

Question 18

Solutions with [H+] < 10^-7 M are what?

Answer 18

basic

Question 19

Human blood is what?

Answer 19

Normally slightly basic with [H+] = 4.0 X 10^-8 M

Question 20

Pure water contains equal what?

Answer 20

equimolar amounts of H+ and OH- so that [H+] = [OH-] = (Kw)^(1/2) = 10^-7 M

Question 21

What is Kw equal to? what about at 25 degrees C?

Answer 21

Kw = [H+][OH-] the value of Kw at 25 degrees C is 10 ^-14 M^2

Question 22

The values of [H+] are usually really small and difficult to compare so a more practical quantity known as:

Answer 22

pH = -log[H+]

Question 23

pH of pure water is what?

Answer 23

7.0 pH

Question 24

Acidic solutions have a pH of what?

Answer 24

pH < 7.0

Question 25

Basic solution have a pH of what?

Answer 25

pH > 7.0

Question 26

For a 1 M solution of a strong acid has a pH of what?

Answer 26

0 pH

Question 27

For a 1 M solution of a strong base has a pH of what?

Answer 27

14 pH

Question 28

If two solutions differ in pH by one unit they differ in [H+] by what?

Answer 28

by a factor of 10

Question 29

[H+] = | in terms of acid and conjugate base

Answer 29

K ([HA]/[A-])

Question 30

pH = -log [H+] substitute the [H+] equation in terms of acid and conjugate base to get what?

Answer 30

pH = -log K + log ([HA/A-])

Question 31

pK =

Answer 31

- log K

Question 32

What is the Henderson- Hasselbalch equation:

Answer 32

pH = pK + log ([A-]/[HA])

Question 33

pH and pk are equal when?

Answer 33

molar concentrations of acid and conjugate base are equal

Question 34

what happens when 0.001 mL of 1M HCL is added to pure water?

Answer 34

Water's pH changes from 7 to 5 thus a fold increase of 100 because 10 for each fold (10 *10 =100) in regards to [H+]

Question 35

At the starting point of a titration what form of the acid-base pair overwhelmingly predominates?

Answer 35

the acid form

Question 36

At the midpoint of titration what form of the acid-base pair predominates?

Answer 36

pH = pK; the acid and conjugate base are equal at this point

Question 37

At the end of titration what form of the acid-base pair predominates?

Answer 37

The conjugate base

Question 38

At the end of titration the amount of strong base added equals what?

Answer 38

equals the equivalents of acid at the starting point

Question 39

The pH at the equivalence point is what? Why?

Answer 39

More that 7 because the reaction of A- with water to form HA + OH-

Question 40

What is the equivalence point?

Answer 40

When the equivalence of string base added (such as OH-) equal the equivalence of HA initially present

Question 41

At the mid point of a titration [HA] =

Answer 41

[A]

Question 42

A weak acid is in the useful buffer range within what?

Answer 42

1 pH unit of its pK

Question 43

What is the useful buffer range of a strong acid?

Answer 43

1 pK unit of pH

Question 44

What is the useful buffer range of a strong base?

Answer 44

Before it exceeds: [A-]/[HA-] > 10

Question 45

Want a buffer around the pH of what?

Answer 45

want a buffer's pK that is around the ideal pH trying to achieve.

Question 46

Substances that bear more than one acid base group are what?

Answer 46

polyprotic acids

Question 47

H3PO4 is an example of what?

Answer 47

polyprotic acid

Question 48

H2CO3 is an example of what?

Answer 48

Polyprotic acid