Chapter 7 Lecture

Question 1

characteristics of acid

Answer 1

• taste sour
• in contact with litmus paper; stained PINK
• reacts and dissolves with some metals
• donated H+ ions!!!!
• always or typically has H-

Question 2

characteristics of bases

Answer 2

• taste bitter
• when in contact with litmus paper; BLUE
• feel slippery
• always donate H+ ions
• typically have -OH

Question 3

conjugates

Answer 3

two compounds (pair) that differ by an H+

Question 4

amphoteric acid

Answer 4

can be an acid or base; water is a specific example

Question 5

equilibrium

Answer 5

when the rate of the forward reaction and the rate of the reverse reaction are equal
**this only refers to the RATES of the reactions, not the CONCENTRATIONS!

Question 6

equilibrium constant

Answer 6

Keq = [C]c[D]d/[A]a[B]b
or = [products]/[reactants]

this equation helps us figure out whether reactants or products are being favored within the equation

Question 7

specific phases to the equilibrium constant

Answer 7

• SOLIDS are always omitted; solid concentrations never change
• SOLVENTS typically omitted; don’t change significantly

Question 8

interpretation of equilibrium constants

Answer 8

Keq > 1 = REACTANTS < PRODUCTS
Keq < 1 = REACTANTS > PRODUCTS
Keq = 1 = REACTANS = PRODUCTS

Question 9

Le Chatelier’s principle

Answer 9

when a reversible reaction is pushed out of equilibrium, the reaction responds to reach a new equilibrium

Question 10

what changes can disrupt an equilibrium?

Answer 10

changes in either:
- concentration
- temperature
- pressure

Question 11

what happens if 2 water molecules react with each other?

Answer 11

creation of both hydronium and hydroxide ions

Question 12

what is the ionization constant of water?

Answer 12

Kw = [H3O+][OH] = 1.0 x 10^-14

Question 13

how is the pH scale determined?

Answer 13

determined through the amount of hydronium (H3O+) ions we have within our solution is:
- acidic
- basic
- neutral

Question 14

pH equation?

Answer 14

pH = -log[H3O+]

Question 15

what is the range of the pH scale?

Answer 15

• scale from 0 - 14
• ACIDIC: x < 7
• NEUTRAL: 7
• BASIC: x > 7

Question 16

describe acid strength

Answer 16

the STRONGER THE ACID = GREATER H3O+ PRODUCTION = LOWER PH

*strong acids = completely ionize
*weak acids = partially ionize

Question 17

what is the acidity constant? (example)

Answer 17

• very similar to the Keq (equilibrium constant equation)
• products/reactants
• the LARGER the Ka = the STRONGER the acid

*correlates wtih pKa = the LOWER pKa = STRONGER the acid

Question 18

base strength

Answer 18

the STRONGER THE BASE = the GREATER -OH PRODUCTION = HIGHER PH

*weak bases only partially ionize

Question 19

neutralization

Answer 19

when an acid and base react to form salt and water
*if proper amounts are added, this will make the solution NEUTRAL (lol get it cause “neutralization”)

Question 20

titration

Answer 20

lab technique used to determine CONCENTRATION of an acid or base solution

Question 21

how does titration work specifically?

Answer 21

• for starters, having an UNKNOWN ACID CONC.
• can use a BASE - KNOWN CONCENTRATION
• to DETERMINE ACID CONC.

Question 22

titration end point

Answer 22

adding enough BASE (known conc.) to consume all ACID (unknown conc.)

*moles of base = moles of acid

Question 23

buffer

Answer 23

solution that is resistant to a pH change when a small amount of acid and base is added

Question 24

how are buffers produced?

Answer 24

weak acid and conjugate base

Question 25

when are buffers most resistant to pH changes?

Answer 25

when pH = pKa of ACID

Question 26

why are buffers important?

Answer 26

if our body is out of buffers, our physiological range(7.35 - 7.45); enzymes are not able to function