Mcat General Chemistry Formulas

Front 1

moles

Back 1

moles= grams/atomic or molecular weight

Front 2

What increases moving from left to right and bottom to top on the periodic table?

Back 2

Energy of Ionization
Electron Affinity
Electronegativity

Front 3

What increases moving from right to left and top to bottom on the periodic table?

Back 3

Atomic Radius
Metallic Character

Front 4

Pico

Back 4

10-12

Front 5

Femto

Back 5

10-15

Front 6

Naming ionic compounds: -ic means what? -ous? Non-metal?

Back 6

ending of cation with greater charge. -ous is for smaller charge. non-metal: -ium.

Front 7

Acids

Back 7

Based on anion. if anion ends in -ide, the acid starts with hydro- and ends in -ic: hydrosulfuric acid H(2)S. If oxyacid, -ic means more O and -ous means less.

Front 8

Binary molecular compounds

Back 8

begins with lowest left and bottom, add -ide to second element with greek prefix.

Front 9

1st quantum number

Back 9

principal quantum number: n. shell.

Front 10

2nd quantum number

Back 10

azimuthal quantum number: l. subshell. s,p,d,f
l=n-1

Front 11

3rd quantum number

Back 11

magnetic quantum number: m(l). Orbital
-l to +l (L)

Front 12

4th quantum number

Back 12

Electron spin quantum number, m(s)
+1/2 or -1/2

Front 13

Pauli Exclusion Principle

Back 13

No 2 electrons can have the same four quantum numbers

Front 14

Heisenberg Uncertainty Principle

Back 14

Can't know both position and momentum with absolute certainty

Front 15

Aufbau principle

Back 15

Each new proton added to creat a new element, a new electron is added as well

Front 16

Hund's Rule

Back 16

Electrons will not fill any orbital in the same subshell until all orbitals in that subshell contain at least one electron, and the upaired electrons will have parallel spins

Front 17

Planck's quantum theory

Back 17

Energy is quantized
dE=hƒ

Front 18

Energy of a photon

Back 18

E=hƒ

Front 19

Photoelectric Effect

Back 19

Particle nature of light
KE of emitted electrons only increases when intensity is increased by increasing the frequency of each photon.

Front 20

Standard Temperature and Pressure

Back 20

STP: 0 C and 1 atm

Front 21

Ideal Gas Law

Back 21

PV=nRT

Front 22

Gas Standard Molar Volume

Back 22

At STP one mole of gas will occupy 22.4 L

Front 23

Partial Pressure of a gas

Back 23

P(a)=X(a)P(total)

Front 24

Dalton's Law

Back 24

P(total)=P(1) + P(2) + P(3)
Ideal gases behave as though they are in a container all by themselves!

Front 25

Average kinetic energy of fluids

Back 25

KE(avg)=3/2RT

Front 26

Graham's Law

Back 26

v(1)/v(2) = √m(2)/√m(1)
rms velocity

Front 27

Effusion. Definition and rate

Back 27

Spreading of a gas from high pressure to very low pressure through a pinhole
effusion rate(1)/effusion rate(2) = √M(2)/√M(1)

Front 28

Real vs. Ideal Gas.
P and V

Back 28

V(real)>V(ideal)
P(real)<P(ideal)

PV/RT should be 1 for an ideal gas. + deviation means deviation due to molecular volume is great. less than 1? deviation due to decreased pressure is greater. Deviations tend to occur at over 10 atms or near boiling point

Front 29

Rate law (generic)

Back 29

rate(forward)=k(f)[A](α)[B](ß)
a+b is overall reaction order (true if elementary reaction)

Front 30

Law of Mass Action

Back 30

K=Products^coefficients/Reactants^coefficients

Front 31

Reaction Quotient

Back 31

Q=Products^coefficients/Reactants^coefficients
Predicts direction of reaction
Greater than K, toward reactants, etc.

Front 32

PV Work

Back 32

W=PdV
Path function
Work is area under curve of P vs. V graph

Front 33

1st Law of Thermodynamics

Back 33

dE=q + w

Front 34

2nd Law of Thermodynamics

Back 34

Heat cannot be changed completely into work in a cyclical process

Front 35

Average kinetic energy of a single molecule in any fluid

Back 35

KE(avg)=3/2kT (k is Boltzmann constant)

Front 36

Enthalpy. Definition and equation

Back 36

Enthalpy is a state function that accounts for the extra capacity to do PV work
dH=dU + PdV
No change in pressure: dH=q

Front 37

Heat of reaction

Back 37

dH(o)=dH(fo products) - dH(fo reactants)

Front 38

Hess' Law

Back 38

The sum of the enthalpy changes for each step is equal to the total enthalpy change regardless of the path chosen.

Front 39

Entropy. Units?

Back 39

dS(system) + dS(surroundings)=dS(universe)≥0
State function
Increases with number, volume, and temperature
J/K

Front 40

3rd Law of Thermodynamics

Back 40

0 entropy for pure substance at absolute zero in internal equilibrium

Front 41

Gibb's Free Energy

Back 41

dG=dH - TdS

constant T
Equilibrium is when G=0
maximum non-PV work available from a reaction

Front 42

Molarity

Back 42

M=mol solute/V of solution
mol/L

Front 43

molality

Back 43

m=mol solute/kg solvent

Front 44

mole fraction

Back 44

X=mol solute/total moles of solute and solvent

Front 45

mass %

Back 45

mass solute/total mass * 100

Front 46

parts per million

Back 46

mass of solute/total mass of solution * 10^6

Front 47

Nitrite

Back 47

NO(2)-

Front 48

Nitrate

Back 48

NO(3)-

Front 49

Sulfate

Back 49

SO(4)2-

Front 50

Sulfite

Back 50

SO(3)2-

Front 51

Carbonate

Back 51

CO(3)2-

Front 52

Bicarbonate

Back 52

HCO(3)-

Front 53

Chlorate

Back 53

ClO(3)-

Front 54

Raoult's Law

Back 54

P(vapor)=X(a)P(a if were pure)
This is for non-volatile

Volatile:
P(vapor)=X(a)P(a) + X(b)P(b)
only true if solute and solvent have similar characteristics (ie a ideal solution)