gen chem

Group 2 elements have what kind of orbitals and are they filled or half filled? Are their electron affinities high or low?

have filled s orbitals so they have stable electron configuration and so electron affinity is low

Group 15 elements have what kind of orbitals and are they filled or half filled? Are their electron affinities high or low?

½ filled p orbitals so their electron affinities are LOWER than group 14 of the same PERIOD

Noble Gas elements are they filled or half filled orbitals? Are their electron affinities high or low?

filled so electron affinities is close to 0

MEMORIZE which elements have what type of orbital

How many electrons fill 1s orbital

2

How many electrons fill 3p orbital

6

how many electrons fill 5d orbital

10

how many electrons fill 7f orbital

14

What are lanthanides

metal elements along Period 6 AND the bottom top period which have lustrous, silvery, high melting point/etc characteristics

What number is the most prominent oxidation state for transition metals

+2

Which groups on the periodic table have s block (orbitals)

Group 1 and 2 (Alkali metal and earth metal)

Which groups on the periodic table have p block (orbitals)

Nonmetals excluding He and H, metalloids, and post transition metals group 13-18

Which groups on the periodic table have d block (orbitals)

transition metals groups 3-12

Which groups on the periodic table have f block (orbitals)

Transition metals Periods 6 and 7 on the bottom most section

What oxidation states do inner transition metals (lanthanides and actinides) have mostly

3+

Where are the actinides on periodic table

Period 7 bottom most on the periodic table below lanthanides

What is the effective nuclear charge equation and what does each component represent

Zeff = Z - S

Z → atomic number (# of protons)

S → # of shielding electrons or inner-shell electrons (EXCLUDING ❌❌VALENCE)

Describe trend of effective nuclear charge (Zeff) on periodic table

increases from left to right across a period and increases moving up a group

Isoelectric series

the same number of electrons (e-) but different number of protons (+)

Monatomic elements

single atom

like Na

Diatomic elements

paired up with another identical atom

How many electrons can the d subshell hold and how many total orbitals are in d subshell

10 electrons, 5 subshells

How to determine Ion Product (IP) contant

1. write out reaction (reactants → products) and then write out the equation

IP= [product1][product2]

3. then substitute the concentrations of the two given products stated in the problem but CONVERT into M (so if mM, convert to M)

4. multiply the two values

this is your IP value

How to determine if a precipitate will form using IP constant

we have to compare ion product constant (IP) value to the given K_sp value in the problem

If IP > Ksp, the rxn is supersaturated and will favor the left side so a PRECIPITATE WILL form

if IP < Ksp, the rxn is not saturated enough, will favor the right side so a Precipitate will NOT form

When to use this equation and what unit of T should I use

when the problem states the volume of gas in L,

and pressure usually in atm,

and a temperature in Celsius.

If the problem mentions any of these variables changing like “pressure decreasing without a change in temperature”

T should be converted to Kelvin

What equation should I use for this problem “A container holds 4.0L of gas at 3.5 atmospheres and a temperature of 27^oC. If the pressure is reduced to 0.8 atmospheres without a change in temperature, what would be the volume of the gas?”

How to calculate Kelvin value when given Celsius

Celsius + 273

How to solve for this problem “A NaOH solution has a molarity of 2.00 M and is titrated with 75.0 mL of 0.500 M H₂SO₄. What volume of NaOH is needed to reach the second equivalence point?”

1. write chemical rxn and balance it

2. H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

3. find the moles of H₂SO₄.

4. find # of moles NaOH is needed to neutralize 1 mol H2SO4 so use the written rxn equation to find this

5. calculate the volume

linear molecule

bond angles are 180 ex: CO2

trigonal planar

bond angles are set to 120.

ex: BF₃

Tetrahedral

four bonds on all 1 central atom. Bond angles are 109.5.

Ex: CH4

Bent/V shape

non linear shape. Angle 105

ex: H2O

common ion effect

if a solution has 2 salts that have same common ion, the common ion supplied by one salt causes this effect that disturbs the solubility equilibrium of the other salt, causing the equilibrium to shift left towards reactants.

According to the following reaction, how many grams of hydrogen gas is formed when 15g of aluminum reacts with excess acid?

2Al + 6HCl → 2AlCl₃ + 3H₂

1. use limiting reagent which in this case is Al

2. convert grams of Al to moles of Al using molar mass

3. then find out moles of Hydrogen made relative to number of moles of Al in reaction

4. convert moles of Hydrogen to grams using molar mass

Which of the following pairs are typically found in alkaline buffer solutions?

Weak base and its conjugate acid

Buffers

resist changes in pH when small amounts of acid or base are added

consist of a mixture of either a weak acid and a salt of its conjugate base, or a weak base and a salt of its conjugate acid.

The acidic component of a buffer can neutralize an added base while the basic component of a buffer can neutralize an added acid. This means that large changes in pH will be repressed

What kind of acid/base is found in alkaline solutions (pH > 7)

weak bases and their conjugate acid

what kind of acid/base is found in acidic solutions (pH < 7 )

weak acid and conjugate base

Which of the following is TRUE for a reaction occurring at 25°C that has a positive ΔH value?

the reaction will be spontaneous if ΔH < ΔS. Why? using ΔG = ΔH -TΔS, where if ΔG is exothermic/spontaneous it has to be (-) so ΔH must be negative or overall value of ΔH - ΔS makes (-) value

specific heat equation

q = mcΔT

q = heat gained (+ value) or lost (- value) in Joules (J)
c = specific heat capacity of an object at a given state

(changes depending on whether it's liquid, solid or vapor phase)

m → mass in grams
ΔT = final temperature - initial temperature

Alkaline earth metal properties

• Appear shiny, silvery-white

• Are somewhat reactive metals🔥

• Have high melting and boiling points

• Form 2+ cations since they have a valance of 2 electrons in their outer shell

Equivalence point

point in which the added titrant is chemically equivalent to the analyte in the sample.

convert M to moles

Molarity (M) x Volume (L)

Molarity unit (M)

mol/L

vaporization is which type of process?

endothermic

all reactions that break bonds are endothermic.

from liquid to gas, we are breaking bonds and thus require the input of heat (endothermic) to derive the reaction forward.

Le Chatelier’s principle

if a system that is in equilibrium is disturbed by changes in temperature, pressure, and concentration of components, the system will tend to shift its equilibrium position to counteract disturbance effect

Which of the following changes to the system would result in an equilibrium shift towards the reactants?

Increasing the volume of the system

increasing the volume of the system would result in an equilibrium shift towards the reactants because this system involves gas molecules, therefore an increase in the volume is accompanied by a decrease in pressure and concentration.

How to find Partial pressure

multiply total pressure by mole fraction of gas

how to find mole fraction

divide the moles of selected gas by the total mole in a system

bronsted lowry base

proton H+ acceptor

Arrhenius bases

dissociate to form hydroxide (OH^-) ions.

Arrhenius acid

dissociate in water, forming proton (H⁺) ions.

Lewis base

electron pair donors

Lewis acid

electron pair acceptors

Bronsted lowry acid

at donates a proton

Rate law problem solving

1. compare 2 rates that have same [] for A or B ‘

2. divide one rate over the other

3. simplify and solve to find x or y variable

4. now substitute the new x or y variable found into exponent and solve the other one using two other rates

Colligative properties

properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the nature of the chemical species present.

ex:

vapor pressure depression 💨💨

boiling point elevation 🔥🔥

freezing point depression 🧊🧊

osmotic pressure 🌊💧

What are the properties of enzymes

• biological catalysts which accelerate chemical reactions by providing an alternative route for the reaction with a lower activation energy

• catalysts increase the rate constant (k) of a reaction

• activation energy is lowered

critical point

A point where the maximum temperature and pressure that allows gas to remain at equilibrium between gaseous and liquid phase

triple point

1. A point at a given temperature and pressure in which the chemical is present in both the solid, liquid and gaseous phase

Half equivalence point

equal numbers of acid and its conjugate base is present.

Equivalence point

when equal moles of base and acid are present during a titration.

Combustion reaction

hydrocarbon or alcohol react with oxygen and products → are CO2 and H2O

empirical formula

formulas that show only the most reduced whole number ratio of each atom

% composition

find the molecule’s molecular weight and then find the desired atom’s total mass in that 1 molecule and then divide that by the big number (molecule’s mass)

“what is the empirical formula of a compound that is 17.3% H and 82.7% C?

assume 100g of total sample. So 17.3% would be 17.3g. Then divide that number by that element’s atomic mass. Same for carbon. Then divide those numbers by which ever number was smaller. If you get decimal number where you cannot round easily, multiple by whole number

“if we have empirical formula C2H5 how do we find molecular formula if molecular weight is 58.12 amuu?”

divide molecular weight by the weight of my empirical formula. Then multiply each subscript of empirical formula with the answer you just got

% yield

actual/theoretical x 100

how to determine which of the two is limiting reagent

smallest value

hybridization how to find

count number of bonds to that carbon (triple and double bonds count as 1 only) and each lone pair counts as 1

For a triple bond, how many sigma and pi bonds are there

1 sigma bond and 2 pi bonds

rank bond lengths based on hybridization

Bond length increases in the order: sp < sp² < sp³.

Most stable resonance structure will have what characteristics

smallest # of charges on overall molecule, and negative charges on most electronegative atoms and positive charges on the least electronegative atoms

Radicals

molecules or atoms with unpaired electrons

“greatest resonance contributor” meaning

which resonance structure is most stable

Newman projections: Eclipsed

least stable

Newman projection": staggered

most stable

Chair confirmation

mass percent equation

at STP, what is the ratio of moles of ideal gas to liters?

1 mole ideal gas / 22.4L

metal oxide

compounds containing oxygen and at least one metal. An example of a metal oxide is iron oxide, which is a major component of rust that forms when iron reacts with oxygen in the air.

Mole fraction

divide the desired molecule’s moles by the total moles of the entire solution with the desired molecule moles

elements in the same group or column have the same

properties

how many electrons are in s subshell

2 electrons

how many electrons are in p subshell

6 electrons

How many electrons are in d subshell

10 electrons

how many electrons are in f subshell

14

How many electrons are in each orbital

2

how many orbitals are in s subshell, p subshell, d subshell, and f subshell

s subshell → 1 orbital

p subshell→ 3 p orbitals

d subshell → 5 d orbitals

f subshell → 7 f orbitals

memorize

memorize

Radio waves (lowest energy) → Microwaves → Infrared → Visible light → Ultraviolet → X-rays → Gamma rays (highest energy)

mnemonic

Roman

Men 👯‍♂️

Invented

Very

Unusual

X-ray 🩻

Guns 🔫🔫

what are some possible values for quantum number n

1,2,3,4…

what are some possible values for quantum number l

0,1,2,3…n-1 where n is the type of orbital and n value given
s=0;

p=1;

d=2;

f=3

what are some possible values for quantum number m_l

-l,…0…+l

what are some possible values for quantum number m_s

+/- (1/2)

how to find electron configuration of an element using noble gas

locate desired element and find the noble gas a period above it (precedes it)

then remaining subscripts should add up to remaining electrons

*HOWEVER if the desired element is a cation, electrons have to be removed from the highest energy level first (so from the last letter configuration so if the last letter was 4p, then take away the electrons from this)

What is the order of filling of electron configuration?

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

then draw out arrows from right to left going down and across

what is Cr electron configuration

[Ar] 4s^1 3d^5

what is Mo electron configuration

[Kr] 5s1 4d1

what is Cu electron configuration

[Ar] 4s1 3d10