Gen Chem 5-6

Front 1

What is the electron config for Cr

Back 1

[Ar] 4s1 3d5

(e- jumps up - only happens with elements under Cr and Cu)

Front 2

What are some words that should let you know the situation is dealing with kinetics

Back 2

Rate, mechanisms, catalyst, intermediate, transition state, activation energy

(how fast something is)

Front 3

What are some words that should let you know the situation is dealing with thermodynamics

Back 3

Stability, equilibrium, spontaneity, energy, entropy, enthalpy, free energy

(how stable something is)

Temp is both kinetics and thermodynamics.

Front 4

Neutralization reactions ________ heat. ∆H is _____

Back 4

Neutralizations release large amounts of heat. ∆H is less than zero

Front 5

What happens to the solubility of calcium carbonate in acid?

Back 5

It increases solubility of calcium carbonate (more dissolution) Carbonate becomes bicarbonate (HCO3 -) and breaks down into CO2 and water.

Front 6

Bronsted, lewis, ad orgo classification for acids

Back 6

-Bronsted: Donate H+

-Lewis: accept E-

-Electrophiles

Front 7

Bronsted, lewis, ad orgo classification

Back 7

-Bronsted: Accept H+

-Lewis: donate e-

-Nucleophile

-(when attached to metal) ligand/chelates

Front 8

General composition for acids and bases

Back 8

Acid: (H-EN)

Base: (EN:)

Front 9

Examples of amphoteric compounds in the body

Back 9

Amino acids - have carboxylic acids and amino groups (characteristics of both acids and bases)

-Water too.

Front 10

Atomic features that increase acidity:

Back 10

-More positve charges (cations)

-More electronegative atoms

-Larger atom increases acidity (IN A COLUMN)

Front 11

Atomic features that increase basicity:

Back 11

-More negative charge

-Less electronegative atoms

-Smaller increases basicity

Front 12

Strong acid will produce a _________ base

Back 12

A strong acid will produce a weak (stable) conjugate base. Not basic conjugate base

Front 13

Strong acid vs. conjugate acid

Back 13

A strong acid will always be stronger than a conjugate acid. A conj acid will not always be a strong acid

Front 14

Which salts are acidic

Back 14

Group I and II cations are NOT acidic

Front 15

NH4Cl is what kind of molecule?

Back 15

It is a salt

-It is acidic since Cl is not basic. Can also think about this in terms of what made this (NH3 + HCl)

Front 16

NaF is what kind of molecule?

Back 16

Made from NaOH + HF (strong base and weak acid = basic)

-Basic salt

Front 17

Which salts are not basic:

Back 17

Cl-, Br-, and I- are essentially not basic

Front 18

NaNO3 is what kind of molecule?

Back 18

Come from NaOH and HNO3

(Strong base + Strong acid = cancel to create neutral)

-Neutral salt

Front 19

Main strong acids to memorize

Back 19

Front 20

Strong bases to memorize

Back 20

Front 21

Kw (standard condition - 25˚C at 1 atm)

Back 21

Front 22

CO3 2-

Back 22

Carbonate

(bicarbonate = HCO3-)

(Carbonic acid = H2CO3)

Front 23

pKa for carbonic acid is 6, so pKb for bicarbonate is _______

Back 23

Front 24

Back 24

Front 25

How to find the pH of a strong acid?

Back 25

Front 26

What is pH of 25mL of 0.025 M HCl?

Back 26

Front 27

What are the pH ranges for a strong acid concentration of:

A. 4x10^-8

B. 6 x 10^3

Back 27

A. 7

B. -4 < pH < -3

Front 28

What is pH of 1L of 2.9 x 10^-4 M of Ca(OH)2 ?

Back 28

Front 29

Formula for finding pH for a weak acid (b/c there is only partial dissociation)

Back 29

Front 30

Back 30

Front 31

How do you find the pOH of a weak base?

Back 31

Front 32

10 moles of compound were added to liter of solution resulting pH was 5.7. What can be said about KA and KB?

Back 32

KB > KA

B/c needed to use 10 moles to have the solution still be mostly neutral. It is a ver weak acid with an overpowering conjugate base.

Front 33

As the electronegativity of a halogen ____, the bond energy _______, and the acidity _______

Back 33

As the electronegativity of a halogen decreases, the bond energy decreases, and the acidity increases.

(H-I has a lower bond energy and is more acidic than H-F b/c it will dissociate more easily)

Front 34

What solvent do you want to use to compare the KA for two strong acids?

Back 34

Use a more acidic solvent than water to compare two strong acids (since they both will find EQ and dissociate completely in H2O)

Front 35

Back 35

Front 36

How would you make a pH 4.5 buffer from either acetic acid, sodium acetate, or both if pKa of acetic acid is 4.5

Back 36

Ways to make a buffer:

1. Add equal moles of HOAc and NaOAc to same beaker

2. Take HOAc and titrate with half the amount of NaOH to get pH 4.5

3. Take NaOAc and titrate with half the amount of HCL to get pH 4.5

Front 37

What's the effect of adding H2O to a buffered solution>

Back 37

-There is no change in pH of buffer

-Diluting the buffer will decrease capacity to buffer (strength) for both acids and bases. A concentrated buffer is a stronger one (could add a lot of acid or pH w/o changing pH )

Front 38

Back 38

-For every 1 pH unit, there is one "9" in the percentage

Front 39

Neutralization b/w _____ & ______. It forms a neutral __________

Back 39

A neutralization rxn happens b/w a strong acid and strong base. It forms a neutral salt and water.

Front 40

Neutralization between a strong acid and weak base forms a ________

Back 40

Neutralization b/w a strong acid and a weka base forms (water and) an acidic salt

Front 41

Normally neutralizations are _____thermic. Complete neutralization means:

Back 41

Normally neutralizations are exothermic. Complete neutralization is when [H+] = [OH-]

Front 42

Titration curve for weak acid w/ strong base (add half amount of base)

Back 42

Front 43

Titration curve for weak base with strong acid

Back 43

Front 44

How does a pH indicator change color?

Back 44

It either becomes protonated or de-protonated.

-once you reach the pKa of the indicator compound. It becomes de-protonated and changes color. (below pKa = still protonated, above pKa = de-protonated)

Front 45

Graph for indicator

Back 45

Front 46

Strong acids to remember (Ka > 1)

Back 46

HI

HBr

HCl

HClO4 (perchloric acid)

H2SO4 (sulfuric acid)

HNO3 (nitric acid)

Front 47

Common strong bases

Back 47

Group I hydroxides (NaOH)

Group I oxides (Li2O)

Some group II OH's (w/ Ba, Sr, and Ca)

Metal amides (NaNH2)

Front 48

Reduction

Back 48

Gaining e-

Gaining H

Loss of oxygens

Decrease in oxidation number

Losing bonds to more EN atom

Gaining bonds to less EN atom

Front 49

Oxidation

Back 49

Loss e-

Loss H

Gain Oxygen

Increase oxidation number

Losing bonds to less EN atom

Gaining bonds to more EN atom

Front 50

Oxidation of H is ____ when bonded to carbon

Back 50

Zero when bonded to carbon

(+1 w/ more EN atom than C , -1 w/ less EN atom)

Front 51

Most reduced = ______ oxidized

Back 51

Most reduced = least oxidized

For e.g. MnCl2, KMnO4, MnO2

MnCl2 (Mn2+) = most reduced/ least oxidized

KMnO4 (Mn7+) = least reduced/ most oxidized

Front 52

Oxidation state for Carbon in CH4

Back 52

Zero. C-H bonds are 0

Front 53

Reduction potential

Back 53

The ability to gain e-

-RP are for the "reactants of the reduction half reactions

-The more positive the reduction potential, the easier it is to reduce to the reactant

--ex. easy to reduce Fl

Front 54

Oxidation potential

Back 54

-OP are for the "products" of reduction half reactions

-OPs are the negative of the reduction potentials

Front 55

Which has the highest reduction potential? Which is the strongest oxidizing agent

Back 55

F2 has the highest reduction potential and it is the strongest oxidizing agent (will rip e- away)

Front 56

Reducing Agents

Back 56

Compounds that cause others to gain e-

-it will lose e- (gets oxidized)

Front 57

Oxidizing Agents

Back 57

Compounds that cause others to lose electrons

-Will gain e-, it gets reduced

Front 58

Which is the strongest reducing agent?

Back 58

Li

-Weakest oxidizing agent is Li+, so its product will be the strongest reducer

Front 59

Relationship between free energy and cell potential

Back 59

Opposite relationship (∆G=-nFEcell)

Cell potential/ Volts needs to be positive for the reaction to be spontaneous (∆G < 0)

Front 60

What is the reaction for this cell (which is oxidized/ reduction)

Back 60

Ag + Pb2+ → Ag+ + Pb

Reactant I Product I I Reactant I Product

Oxidation I I Reduction

Anode I I Cathode

Front 61

______ occurs at the anode, and ______ occurs at the cathode

(Redox)

Back 61

Oxidation → Anode

Reduction → Cathode

Front 62

If the cell potential is Ecell < 0, the cell is ________

Back 62

(Negative) E volts => nonspontenous cell

Front 63

If the cell potential is Ecell > 0, the cell is ________

Back 63

(Positive) Ecell => Spontaneous cell

Front 64

Formula for current while electroplating (Farady's)

Back 64

F => Farady's constant

Front 65

Relationship b/w Amp and Coulomb?

Back 65

Roughly equal

Front 66

What is an electrochemical cell consist of?

Back 66

A. 2+ electrodes made from conductive material (usually metal and graphite)

B. An electrolyte bridging the gap b/w the electrodes (aka salt bridge)

C. A circuit to connect the 2 electrodes which can contain either resistance or power source (if you have a power source = non-spontaneous rxn occurring)

Front 67

Galvanic cell (aka votlaic cell)

Back 67

Galvanic cell will be part of a complete circuit w/ NO external power source

--Spontaneous, positive Ecell (neg ∆G)

--discharging battery (e.g. used in a device)

--Opposite kind of cell => electrolytic cell

Front 68

Electrolytic Cell

Back 68

Electrolytic cell will be part of a complete circuit with an external power source

--Non-spontaneous, negative Ecell (∆G = pos)

--Recharging battery

--Opposite of galvanic cell

Front 69

In a battery, which way to electrons flow?

Back 69

Anode → Cathode

(oxidation) → (reduction)

Front 70

Purpose of salt bridge in a battery?

Back 70

Neutralize solns where anode soln gets (+) and cathode soln gets (-). Allow current of e- to keep flowing

Front 71

Anode

Back 71

(Negative) electrode of battery.

-Origin of e- current/flow

-Oxidation takes place

-Anions in battery move towards the anode (b/c its losing electrons)

Front 72

Cathode Diagram

Back 72

Front 73

Which is anode and cathode

Back 73

Front 74

_____ occurs at the cathode and ______ from salt paste/bridge move towards the cathode. Also, current flows _____ cathode

Back 74

Reduction at the cathode

Cations move towards the cathode

Current flows from cathode

Electroplating occurs

Front 75

Current flows (opposite/ in line with) electron flow

Back 75

Current flow opposite of electrons.

Current (I) flows from positive → negative

Front 76

Back 76

Front 77

Back 77

Dead batter. Ecell = 0

Front 78

Ecell for each scenario:

Discharging battery

Dead battery

Recharging battery

Back 78

Discharging = pos

Dead battery = 0

Recharging battery = neg (forcing battery to reset/ non-spontaneous)

Front 79

Which is the anode and cathode for this recharging battery?

Back 79

Front 80

The anode is where....

(in terms or A. redox, B. ions. C. current)

Front 81

When is a battery at equilibrium?

Back 81

When the battery has no charge (it's dead)

Ecell = 0

∆G = 0

Front 82

Alpha particle

Back 82

Front 83

Alpha Decay

Back 83

Z ⇰ Z - 2

Emit alpha particle (helium)

Atoms w/ large nuclei mainly undergo this decay

LEAST dangerous type of ionizing radiation

Small penetration - can be stopped by Al foil

Front 84

Alpha exposure vs contamination

Back 84

Alpha radiation is least dangerous type b/c is has weak penetration (large particle)

-It can be stopped by piece of Al foil

-However, contamination is bad b/c it means that the radiation is inside the body

Front 85

Beta emission

Back 85

Z ⇰ Z +1

Subtracting electron (NO MASS)

Add a proton

Front 86

Beta emission particle

Back 86

Z ⇰ Z +1

Mass # stays the same

Add a proton

Front 87

Beta Positron emission

Back 87

Front 88

Beta electron capture

(looks a lot like positron emission - so need to see if something was absorbed or emitted)

Back 88

Front 89

Which are safer, longer or shorter half life decays?

-How many half lives to become safe?

Back 89

Longer half lifes tend to be safer

-need to take in account the type of decay

~10 half lives needed for compound to become safe.

Front 90

Binding energy

Back 90

Front 91

Concentration Cells

Back 91

Galvanic cells that have identical electrodes but with has half-cells w/ different ion concentrations

-Not at standard cell voltage (E˚)(zero) b/c electrolytic solutions in the half cells are not 1 M. The concentration diff runs the current. (less conc -> more conc)

-Lesser concentration = anode

-Higher concentration = cathode

Front 92

Concentration cell Diagram

Back 92

Front 93

Titration curve

Back 93

Front 94

Equivalence point for a strong base and strong acid titration

Back 94

Where the moles of H+ = OH-

-Will be at pH = 7

-Only salt is present in solution

-You have added the full amount of base to deprotonate all the acid

Front 95

Back 95

TRICK QUESTION!!! It's giving pKb

pI is determined by pKa

14 = pKa + pKb

Cysteine has a pKa of 5 - so need an indicator with a pKb of (14-5) 9

Front 96

Titration curve for diprotic acid with strong base

(what can be said about buffer regions)

Back 96

Front 97

Buffer region on titration curve

Back 97

You have equal concentrations of your acid and conjugate base

-you have half the amount of base to deprotonate your acid

-It also tell you have many acidic protons you have in your molecule

-Determines the pKa

Front 98

Back 98

Titration curve for amino acids

-Acidic and basic AA will have 3 pKa's ∴ 3 buffer regions

-3 end points, but only one pI (pI will give zwitterion)

Front 99

How to find equivalence point

Back 99

Front 100

How to find half equivalence point in titration

Back 100

Front 101

End point in titration

Back 101

It is the point where molecule is 100% deprotonated

-Can use an indicator that as pKa 1 unit of molecule pKa (color change)