CHE Final Exam

Question 1

Alpha and beta particles

Answer 1

Positively and negatively charged particles, respectively

Question 2

Gamma rays

Answer 2

Neutral charge, high-energy radiation

Question 3

Nuclear theory

Answer 3

Supported by Rutherford’s experiment:

nucleus = most of atom’s mass w/protons & neutrons

empty space = most of atom’s space w/electrons

Question 4

Polyatomic molecules in nature

Answer 4

P₄
S₄
Se₄
O₃

Question 5

Noble metals

Answer 5

Ag, Pt, Au

Question 6

Transition metals with predictable charge (3)

Answer 6

Ag (1B = 1+)
Zn (2B = 2+)
Cd (2B = 2+)

Question 7

1 prefix (HC)

Answer 7

meth-

Question 8

2 prefix (HC)

Answer 8

eth-

Question 9

3 prefix (HC)

Answer 9

prop-

Question 10

4 prefix (HC)

Answer 10

but-

Question 11

HC suffixes (single, double, & triple bonds)

Answer 11

-ane, -ene, -yne

Question 12

Alkanes

Answer 12

Hydrocarbons with only single bonds (-anes)

Question 13

Percent yield

Answer 13

% yield = ( actual / theoretical ) * 100%

*NOT PERCENT ERROR!

Question 14

Dilution formula

Answer 14

M₁V₁ = M₂V₂

M = molarity, V = volume (liters)

Question 15

Dissociation

Answer 15

Ions of a salt separate when dissolved

Question 16

Ionization

Answer 16

Process of ion formation in solution

(acids, bases)

Question 17

Arrhenius acids & bases

Answer 17

Acids produce H⁺ (H₃O⁺) in water

Bases produce OH^- in water

Question 18

Brønsted acids & bases

Answer 18

Acid = proton donor

Base = proton acceptor

Question 19

Monoprotic, diprotic, and tripotic acids

Answer 19

Each unit of acid yields one, two, and H⁺ ion(s) respectively

Question 20

Neutralization reaction result

Answer 20

salt + water + heat

Question 21

Gas-evolving reactions & compounds (4)

Answer 21

Acid + salt –> salt + gas + water

Sulfides

Bicarbonates

Bisulfites

Ammonium

Question 22

Oxidation half-reaction

Answer 22

Shows loss of electrons (OIL)

Question 23

Reduction half-reaction

Answer 23

Shows the gain of electrons (RIG)

Question 24

Oxidizing agents

Answer 24

Are reduced (RIG)

Question 25

Reduction agents

Answer 25

Are oxidized (OIL)

Question 26

Disproportionation reaction

Answer 26

Same element is simultaneously oxidized & reduced

Question 27

Modified dilution equation

Answer 27

M_acidV_acid(# of H⁺) = M_baseV_base(# of OH^-)

Question 28

Pressure unit conversion

Answer 28

760 mmHg = 760 torr = 1 atm = 101,325 Pa

Question 29

Molar mass of gas formula

Answer 29

M = dRT/P

molar mass = (density) * R * (Kelvin) / (atm)

D = PM/RT
= pressure * molar mass / R * temp

Question 30

Average KE

Answer 30

Constant tempterature: gases have same average KE

Question 31

Root mean square velocity

Answer 31

u_rms = (3RT/M)^1/2

R = J/mol K
T = Kelvin
M = kg/mol

Question 32

Graham’s law of effusion

Answer 32

r_a/r_b = (M_{<span>b</span>}/M_{<span>a</span>})^1/2

Question 33

Real gases

Answer 33

Behavior differse at high pressure/low temperature

Question 34

Energy unit conversion (4 equalities)

Answer 34

1 J = 1 kg*m²/s²

1 cal = 4.184 J

1 Cal = 1kcal

1 L*atm = 101.3 J

Question 35

Internal energy & change in internal energy

Answer 35

E (internal energy) = KE + PE

ΔE = E_products - E_reactants

ΔE = q + w

*+w work done ON system, -w work done BY system

ΔE_system = -ΔE_surroundings

Question 36

Pressure-volume work

Answer 36

w = -PΔV

work = negative of external pressure * change in volume

Question 37

Enthalpy/change in enthalpy formula

Answer 37

Enthalpy = H

H = E + PV
(internal energy + pressure*volume)

ΔH = ΔE + PΔV

ΔH = H_products - H_reactants

Question 38

Heat capacity

Answer 38

q = C * Δt

Amount of heat to raise temperature by 1°C

C = J/°C or J/K

System absorbs heat = temperature increasse

Question 39

Specific heat capacity

Answer 39

q = m * C_s * Δt

Measure of substance’s ability to absorb heat/amount of heat required to raise 1 g of substance by 1°C

Question 40

Bomb calorimeter

Answer 40

Constant-volume calorimetry

ΔE_rxn = q_v = q_rxn = -q_cal

q_cal = C_cal * ΔT = -q_rxn

Question 41

Coffee-cup calorimetry

Answer 41

Constant-pressure calorimetry

ΔH_rxn = q_p = q_rxn = -q_soln

q_soln = m_soln * C_{s, soln} * ΔT = -q_rxn

Question 42

Standard enthalpy of formation

Answer 42

ΔH_f°

Heat change when one mole is formed from elements at 1 atm

Most stable = 0

Stable liquids: Hg, Br

Stable gases: H₂, N₂, O₂, F₂, Cl₂, noble gases

Graphite is stable, diamond is not

S₈ rhombic is stable

Question 43

Standard enthalpy of a reaction

Answer 43

The enthalpy of a reaction carried out at 1 atm

ΔH_rxn° = Σn_productsΔH_f° - Σn_reactantsΔH_f°

Question 44

Hess’ law

Answer 44

ΔH_rxn° = ΔH₁° + ΔH₂°

Question 45

Frequency formula

Answer 45

v = c / λ

Question 46

Electromagnetic spectrum

Answer 46

Low energy to high:

radio
microwave
infared
visible light
ultraviolet
X-ray
gamma ray

Question 47

Photoelectric effect

Answer 47

Many metals emit electrons when light shines on surface

Question 48

Number of photons formula

Answer 48

Number of photons = E_pulse / E_photon

*E_photon = hc/λ

Question 49

Energy & frequency combined formula

Answer 49

v = c / λ

E = hv

E = hc/λ

Question 50

Wavelength formula

Answer 50

λ = h/mv

Planck’s constant / mass * velocity

Question 51

Energy of electron orbital change formula

Answer 51

ΔE_{H atom} = -R (1/n²_final - 1/n²_initial)

R = Joules

Question 52

1 Hz = ? s^-1

Answer 52

1 Hz = 1 s^-1​

Question 53

Pauli exclusion principle

Answer 53

No two electrons can have same four quantum numbers

Orbital = 2 electrons max

Question 54

Aufbau principle

Answer 54

Lower energy orbitals fill before higher energy orbitals to minimize energy of atom

Question 55

Hund’s rule

Answer 55

Electrons first occupy orbitals of equal energy singly with parallel spins

Question 56

Transition elements with irregular electron configurations (10)

Answer 56

1. Cr (Chromium) 24
2. Cu (Copper) 29
3. Nb (Niobium) 41
4. Mo (Molybdenur) 42
5. Ru (Rutherium) 44
6. Rh (Rhodium) 45
7. Pd (Palladium) 46
8. Ag (Silver) 47
9. Pt (Platinum) 78
10. Au (Gold) 79

Question 57

Van der Waals radius

Answer 57

Nonbonding radius of an atom

Question 58

Cation v. anion radius size

Answer 58

Cations < anions

Except Rb+ and Cs+ are larger than F- and O2-

Question 59

Periodic trends in first ionization energy

Answer 59

The larger the Zeff, the more energy it takes to remove it.
*IE1 increases to the right
**Except: Group 2A to 3A & Group 5A to 6A

The farther the electron is from the nucleus, the less energy it takes to remove it
*IE1 decreases toward the bottom

Question 60

Electron affinity

Answer 60

X (g) + e- → X- (g) + EA

The energy released (-kJ/mol) when a neutral gaseous atom gains an electron

The more energy released when electron is gained, the more negative the EA (-kJ/mol)

*INCREASES TO THE RIGHT

Question 61

Diagonal relationship

Answer 61

1. Li & Mg
2. Be & Al (Al is a metal like 2A)
3. B & Si (metalloids)

Similar because of charge density (ion charge / volume)

Question 62

Properties of oxides across a period (3)

Answer 62

1. Metals/Groups 1A/2A form basic oxides
2. Nonmetals form acidic oxides
3. Al form amphoteric oxides (both basic/acidic)

Question 63

Formal charge (4)

Answer 63

Charge an atom would have if all bonding electrons were shared equally

FC of an atom = Valence e- - nonbonding e- - (1/2)(bonding e-)

1. Sum of all formal charges in neutral molecule = 0
2. Sum of all formal charges in ion = ion charge
3. Small (or zero) formal charges on individual atoms are better than large ones
4. When formal charge cannot be avoided, negative formal charge should reside on the most electronegative atom

Question 64

The Clausius-Clapeyron Equation

Answer 64

ln P₂/P₁ = (-ΔH_vap/R) (1/T₂-T₁)

R = 8.314 J/mol K

T = in Kelvin

Question 65

Equation for heat involved in completion of a phase change

Answer 65

q = nΔH_transition

heat = # of mols * heat of [transition]

Question 66

Equation for heat involved in temperature change

Answer 66

q = (m) (Cs) (ΔT)