Acids/Bases: Quiz 3

Question 1

weak acid law

Answer 1

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

Question 2

calculations that require an ICE box

Answer 2

asked to find [H3O+], pH, Ka, or initial concentration

Question 3

percent ionization equation

Answer 3

equation used to support the assumption that the value of x in the [HA] at equilibrium is neglible

Question 4

%I=

Answer 4

[H3O+] at equilibrium / [HA] x100

Question 5

hydrolysis

Answer 5

reaction between an ion and water that produces a conjugate acid or base that effects the concentration of hydronium or the hydroxyl ion; the parent acid and parent base of a salt helps predict the change in [H3O+] or [OH-]

Question 6

hydrolysis: neutral salts

Answer 6

a salt that contains the anion of a strong acid and the cation of a strong base that produces a neutral solution in water

Question 7

hydrolysis: basic salts

Answer 7

salts that contain the cation of a strong base and the anion of a weak acid that form a basic solution in water

Question 8

hydrolysis: acid salts (type 1)

Answer 8

salts that contain the cation of a weak base and the anion of a strong acid that produces an acidic solution in water

Question 9

hydrolysis: acid salts (type 2)

Answer 9

salts with the anion of a strong acid and the cation is a small highly charged metal ion that produces an acidic solution in water; Al, Fe, Cr, Sn, Cu, Be; 6 water molecules react with them

Question 10

hydrolysis: mixed salts

Answer 10

salts that contain the anion of a weak acid and the cation of a weak base that can produce either a basic or acidic or neutral solution; write the hydrolysis equation for both ions and then look up or calculate the Ka and Kb values to determine the pH prediction of the solution in water

Question 11

hydrolysis: salts with amphiprotic ions

Answer 11

salts with the cation of a strong base and the anion is amphiprotic that can produce an acidic, basic, or neutral solution

Question 12

buffer

Answer 12

solution that resists changes in pH following the addition of relatively small amounts of a strong acid or base; usually made from a weak acid and its conjugate base; the concentrations of the weak acid and conjugate base should roughly be equal and be of appreciable concentrations

Question 13

2 factors that affect the pH of a buffer

Answer 13

1. Ka value
2. ratio between the weak acid and its conjugate base concentrations

Question 14

acid buffers

Answer 14

buffers that are in the acidic range of the pH scale

Question 15

base buffers

Answer 15

buffers that are in the basic range of the pH scale

Question 16

[OH-]=

Answer 16

Kb[B]/[HB+]

Question 17

[H3O+]=

Answer 17

Ka[HA]/[A-]

Question 18

Henderson-Hasselbalch Equation def

Answer 18

equation used when preparing a buffer to target a specific pH; use this on AP exam when doing buffer calculations

Question 19

Henderson-Hasselbalch Equation

Answer 19

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

Question 20

buffer capacity

Answer 20

amount of an acid or base that a buffer can neutralize before pH drastically changes; high capacity buffers neutralize acids and bases better than low capacity buffers, but high capacity buffers are more reactive

Question 21

to be effective, the ratio of the weak acid concentration to the conjugate base concentration must be in a range:

Answer 21

10> [A-]/[HA] > 0.10
-ideally the ratio should be 1.0

Question 22

calculating the volume of a titrant given pH

Answer 22

using the antilogarithm of the pH or pOH as well as stoichiometry, the volume of the titrant can be calculated

Question 23

calculating percent purity

Answer 23

impure solid acids and bases can be dissolved in pure water and the mass of the pure solid can be calculated through stoichiometry

Question 24

percent purity equation

Answer 24

mass of pure solute/mass of impure solute x 100

Question 25

acid-base indicators

Answer 25

solution that changes color in the presence of an acid or base

Question 26

endpoint/transition point

Answer 26

point in the titration where the indicator changes color

Question 27

universal indicator

Answer 27

indicator made of lots of acid-base indicators that can turn every color of the rainbow; due to the complexity of indicator molecules, short-hand is used

Question 28

at the endpoint,

Answer 28

[in-]=[Hin], Ka=[H3O+], pKA=pH