General Chemistry 2 ACS Final

Hydrogen Bonds form between _____ .

hydrogen and highly electronegative atoms (i.e. H2O and NH3)

What substance is most soluble in water?

alcohol (i.e. ethanol)

Soluble solutions (miscible):

-polar + polar

-nonpolar + nonpolar

Insoluble solutions (immiscible):

-nonpolar + polar

Polar Molecules typically contain ____ .

asymmetry or hydrogen bonds

Relationship between volume, mass, and density:

-D = M/V

-V = M/D

-M = DV

Relationship between mass, moles, and volume (Hint: Molarity M):

-mol = M/molar mass

-Molarity = mol/V(L)

Molality m:

moles of solute/kg of solvent

ppm

mass of solute/mass of solution x 10^6 (mg/Kg)

ppb

mass of solute/mass of solution x 10^9 (mg/Kg)

Saturated

produces solid/heterogenous

Unsaturated

homogenous

Supersaturated

no solid/increase in concertation

Partial Pressure

-S = kP

-k = S/P

Solubility of Gases

-lower temperatures

-higher pressures

Freezing point:

Tf = Kf x molality

Boiling point:

Tb = Kb x molality

Which information needs to be measured in order to determine molar mass of a solution?

-pressure

-temp

-volume

-mass

Osmotic Pressure

pi = iMRT (i = # of ions)

Highest Osmotic pressure is determined by:

-more ions

-higher concertation

Reaction order

the exponents in reaction rate (i.e. x for [Na]^x)

Reaction Rate

-Speed at which reactants convert to products

-products/reactants (for gas/aq)

Half-life Equation to get mass and time:

-mass = Ao(1/2)^t/years(half life)

-At=Ao(e)^-landa(t), then ln(2)/landa

Why is activation energy changed by adding a catalyst?

catalyst changes the reaction mechanism

What is true about higher activation energies and temperature?

higher activation energies are more effected by a change in temperature

What increases the value of k for an elementary step?

raising temperature

According to Arrhenius equation ____ .

at constant temp, reactions with lower activation energies will proceed more rapidly.

K>Q

shift towards products

K

shift towards reactants

K>1

product favored

How will increase in temp effect these types of reactions?

a) endothermic

b) exothermic

a) heat is added to reactant (+), increases

b) heat is added to product (-), decreases

How to calculate activation energy:

ln k1 = -Ea/RT + ln k2

or

ln (k2/k1)= -Ea/r (1/T1 -1/T2)

Single step reaction:

Kc= Kf/Kr

Equilibrium:

-concentration of substances are "="

-forwards and reverse reaction are "=" speeds

k tells you:

-direction of reaction

-quantity of reactant remaining

-extent of reaction

Kc > 0

more product

Kc < 0

more reactant

What happens when volume is decreased at constant temperature?

reactions shifts towards reactants

What happens when you decrease temperature of a reaction?

it favors products

What happens when you increase pressure of a reaction?

it favors products

Arrhenius acid

Produces H+ ions when dissolved in water

Arrhenius base

Produces OH- ions when dissolved in water

Lewis acid

electron acceptor

Lewis base

electron donor

Lowry Acid

H+ donor

Lawry Base

H+ acceptor

Henderson-Hasselbalch equation (strong/weak)

pH = pKa + log [base]/[acid]

What changes with strength when oxygen is added to an acid?

-the more oxygen, the stronger

-other element is determined by electronegativity

How to determine strength of an acid?

The size of the element: the larger, the stronger

How to calculate H+ concentration:

10^-pH

How to calculate OH- concentration:

10^-pOH

How to calculate pH:

pH = -log[H+]

How to calculate pOH:

pOH = -log[OH-]

Criteria for spontaneity?

-delta S>0

-delta G<0

How to calculate delta S:

-S products - S reactants

-(delta H- delta G standard)/Temperature

Factors that increase entropy:

-phase

-# of gas particles

-pressure

-volume

-complexity

-weight

-s->l->g

-more gas

-less pressure

-increased volume

-more complexity

-heavier

Delta G calculations:

G=H-TS

G=G standard + RTlnQ

How to calculate G standard:

-RTlnK

Calculation for Keq:

e^-G standard/(RT)

Anode

Oxidation (-)

Cathode

Reduction (+)

How to calculate Ecell:

Reduction + Oxidation

Ecell>0

spontaneous

Strongest oxidizers

most positive

Strongest reducers

most negative

Alpha addition

add p+ and n

Alpha emission

removes p+ and n

Beta decay (positron emission)

turns n->p+

What kind of nuclear reaction causes no change?

gamma

Fusion

before curve

Fission

after curve