acids & bases

Question 1

6 strong acids to recognize

Answer 1

HCl, HBr, HI, HClO4, HNO3, H2SO4

Question 2

12 strong bases to recognize

Answer 2

hydroxides of first two columns of periodic table, excluding hydrogen (like NaOH, KOH, Ca(OH)2)

Question 3

what happens if an acid and a base with equal molarities, both strong or both weak present in solution

Answer 3

neutralize each other completely, pH = 7

Question 4

what is Na+ generally

Answer 4

spectator ion

Question 5

determining change in concentration given concentrations of both reactants

Answer 5

change equals concentration of limiting reactant

Question 6

bronsted-lowry acid

Answer 6

proton donor

Question 7

bronsted-lowry base

Answer 7

proton acceptor

Question 8

conjugate acid-base pairs relationship

Answer 8

differ by one proton

Question 9

Reaction quotient Q - what is it and how do you find it??

Answer 9

describes a reaction with forward and backward movement, and shows to which side the reaction favours

Q = [prod 1]^coefficient prod 1 * [prod 2]^coefficient prod 2/ [reactant 1]^coeff reactant 1 * [reactant 2]^coeff reactant 2

CONCENTRATION OF LIQUIDS AND SOLIDS IGNORED, APPROX EQUAL TO 1**

Question 10

equilibrium

Answer 10

point where no further change in concentration of prod and reactants

Question 11

equilibrium constant K

Answer 11

same as reactant quotient - K = concetnration reactnats ^ coefficients/ concentration products ^ coefficients

Question 12

what is implied by different Q values?

Answer 12

if Q = K then system is in equilibrium

if Q > 1, more products

if Q < 1, less products

Question 13

acid dissociation reaction

Answer 13

reaction of acid in water to produce conjugate base and H3)

Question 14

Ka

Answer 14

K value (equilibrium) for acid dissociation rxn acid + water –> conj base and H3O+

Question 15

pKa / pKb

Answer 15

= -log(Ka)

describes the strength of an acid or base, small pKa/b = strong acid/base

Question 16

what does being a strong acid imply

Answer 16

dissociate pretty much to completion

will have a large Ka and smapp pKa

Question 17

base ionization reaction

Answer 17

rxn of a base with water to produce conj acid and OH-

Question 18

what does being a strong base imply

Answer 18

dissociate almost to completion

high Kb value (prod favoured)

low pKb

Question 19

Kw

Answer 19

equilibrium constant of the reaction of water and water —> H3O + OH-

= 10^-14

product of [H3O] and [OH] ALWAYS equals 10^-14

because the concentration of water is ignored

therefore, pure water at 25 degrees C [H3O]=[OH-]=10^(-7)

Question 20

pH calculation

Answer 20

pH = -log[H3O]

Question 21

pOH calculation

Answer 21

pOH = -log[OH]

Question 22

relationship pH and pOH

Answer 22

always = 14

Question 23

pH of acids vs bases

Answer 23

acid pH <7

base pH>7

Question 24

calculate [H3O] or [OH] from pH of pOH

Answer 24

[H3O] = 10^(-pH)

[OH] = 10^(-pOH)

Question 25

calculate [H3O] or [OH] from pH of pOH

Answer 25

[H3O] = 10^(-pH) [OH] = 10^(-pOH)

Question 26

relationship between Ka and Kb

Answer 26

Ka*Kb= Kw Ka = Kw/Kb Kb = Kw/Ka stronger acid means weaker base, large Ka small Kb and same for reverse

Question 27

why are extends of weak acids and bases important?

Answer 27

living things are sensitive to very small changes in pH

Question 27

why are extends of weak acids and bases important?

Answer 27

living things are sensitive to very small changes in pH

Question 28

changing pH of salt solutions - what happens???

Answer 28

salts are ions held together by ionic bonds dissociate in water, solution of ions ions can act as an acid or base, reaction with water which changes concentration of [H3O] or [OH]

Question 29

salts with a strong acid and base form ___ solution

Answer 29

neutral

Question 30

salts with strong base and weak acid form ____ solution

Answer 30

basic solution

Question 31

salts of weak base and strong acid form ____solution

Answer 31

acidic solution

Question 32

buffer solutions

Answer 32

resist change in pH from addition of small amount strong acid or base if excess H3O or OH in solution will react with wither acid or base already present to neutralize, small change pH formed from solution of strong acid and weak base or weak acid and strong base in solution in appreciable amounts

Question 33

how to tell if something is a buffer numerically

Answer 33

the concentration of the acid and conjugate base or base and conj acid must be within x 10 of each other

Question 34

strategies for making buffer solution

Answer 34

1. mix weak acid and salt of it's conjugate base (ex. CH3COOH and CH3COONa) 2. mix weak base and salt of it's conjugate acid (ex. NH3 and NH4Cl) 3. react weak acid w strong base 4. react weak base and strong acid ****conj acid-base concentrations MUST be within 10x of each other

Question 35

how can you calculate the pH of a buffer solution???

Answer 35

henderson-hasselbach equation pH = pKa + log (base/acid)

Question 36

concentration of [H3O] given concentration of conjugate acid and base and Ka

Answer 36

[H3O] = Ka[HA]/[A-]

Question 37

assumptions for henderson-hasselbach equation

Answer 37

-1 < log(base/acid)<1 (the within 10x thing) works best for weak acids and weak bases, not to use when strong acid or strong base as a reactant

Question 38

important thing to remember when using rice tables to calculate pH

Answer 38

account for concentrations of products already in the solution