Chem ch 16

Question 1

Bases and acids are __________

Answer 1

Opposites

Question 2

pH - what does it mean?

Answer 2

Power of Hydrogen (regarding solutions)
Measures Hydrogen ions

Question 3

pOH – what does it mean?

Answer 3

Describes hydrogen ion concentration
Measures Hydroxide ions

Question 4

What is the pH and pOH scale based on?
(hint: HijklmnO)

Answer 4

Ionization constant of water

Question 5

What does the pH scale tell you?

Answer 5

How acidic or basic/alkaline a substance is

Question 6

What does the pOH scale tell you?

Answer 6

Hydroxide ion concentration

Question 7

pH = 7 what does that tell you?

Answer 7

Neutral solution

Question 8

pH <7 - what is it?

Answer 8

Acid

Question 9

pH >7 - what is it?

Answer 9

Base

Question 10

pOH <7 - what is it?

Answer 10

Base

Question 11

pOH >7 - what is it?

Answer 11

Acid

Question 12

pOH =7 - what is it?

Answer 12

Neutral

Question 13

Strong acid

Answer 13

Give up protons (H+) easily
Ionize completely (not shared!)
Dissolves well in water
Ex: HCl (stomach acid)

Question 14

Weak acid

Answer 14

Don’t dissociate (separate) completely into ions
Dissolves poorly in water
Ex: Vinegar

Question 15

Strong Base

Answer 15

Accept protons (H+) readily
Dissolves well
Ex: NaOH (dissolve 95%)

Question 16

Weak Base

Answer 16

Poor proton (H+) acceptors
Doesn’t dissolve well
Ex: NH3 (dissolve 5%)

Question 17

Acid + base -> _________+____________

Answer 17

H2O + Salt

Question 18

If you look at a glass of water, are 100% of the water in there is H2O?

Answer 18

No there is self-ionization meaning water can react with itself and form different combinations

Question 19

Conjugate base – how is it formed? What is it?

Answer 19

Everything tht remains of the acid molecule after a proton (H+) is lost
Acid (loses H+) –> conj base

Question 20

Conjugate acid – how is it formed? What is it?

Answer 20

Formed when the proton (H+) is transferred to the base
Base (gains H+) –> conj acid

Question 21

Oh my lady gaga you spilled base on your arm! How do you respond to neutralize it?

Answer 21

Put acid on it

Question 22

Titrations – what are they

Answer 22

Controlled neutralization reactions used to determine the unknown concentration of a solution

Question 23

Equivalence point – what is that?

Answer 23

Equal moles of acid and base (in a titration)

Question 24

End point – what is that?

Answer 24

The point in a titration at which the indicator changes color (when pH 7.0 is met - true for strong acids and bases only)

Question 25

MaVa = MbVb <– what does this formula tell you? How do you use it?

Answer 25

Equation for solving unknown MOLARITY concentrations (M)
known known = unknown unknown

Question 26

Buffer – what is it? How many times do you need to poke someone else before they react? (Think about class!)

Answer 26

Solutions tht resist changes in pH (balance pH)
Cancels out acids/bases
Weak acid & conj base OR Weak base & conj acid

Most effective @ regulating SLIGHT pH changes
Ex: Human blood btwn pH 7.35-7.45

Question 27

Bronsted-Lowry acid and base – how are they defined?

Answer 27

Acid donates a proton (H+) (deprotonation)
Base accepts a proton (protonation)

Question 28

Arrhenius Model

Answer 28

Acids release H+ (hydrogen) into solutions
Bases release OH- (hydroxide) into solutions
Problem: Hydrogen-containing compounds are not always acids - only deals w compounds in aqueous solutions

Question 29

Lewis Model

Answer 29

Acid - substance tht accepts pair of electrons
Base - substance tht donates a pair of electrons
Broader definition

Question 30

How do we measure pH?

Answer 30

Universal indicators (substances whose colors are sensitive to pH)
Ex: pH meters, papers

Question 31

Base characteristics

Answer 31

Bitter
Feels slippery
Some are electrolytes (substance that ionizes [+ -] to conduct electricity in a solution)
pH above 7

Question 32

Acid Characteristics

Answer 32

Sour
Electrolyte
React w active metals to produce Hydrogen gas and a salt
pH below 7