chem 1 equations and reviews

chem 1031

equation to find energy of a photon when given photon velocity

E = hv

E = energy of photon

h = plank’s constant

v = photon velocity

equation to find energy of a photon when given wavelength

E = (hc)/λ

find number of photons from energy in the pulse and energy in 1 photon

energy in pulse (J) / energy in 1 photon (J)

relationship between energy, frequency, and wavelength

length and frequency inverse relation, length and energy inverse relation, frequency and energy correlated relation

explain the bohr atom and energy release

• electrons can only exist at specific quantized distances from nucleus

• higher distance from nucleus = higher potential energy

• when an electron falls from a high energy n level to a lower energy n level, there is a release of energy

• the release of energy from transitions between orbits create an emission of light

find speed of a wave

v = f * λ

find velocity of an electron from wavelength

λ = h / (m*v)

m is mass in kilograms

wave and particle nature of light

• only light above a certain threshold frequency can dislodge electrons

• light shone on a metal releases electrons

• light energy comes in “packets”, showing it is quantized amounts

4 quantum numbers

• n: determines overall size and energy

• l: shape of orbital, # of nodes, =n-1

• ml: orientation of orbital, =-l … +l

• ms: spin of electron, +-1/2

periodic trend for size

downwards bigger, right smaller

ionization trend on table

downwards decreases, right increases

electronegativity trend on table

downwards decreases, right increases

electronegativity scale

0 - 0.4 nonpolar covalent

0.4 - 2.0 polar covalent

>2.0 ionic

subtract electronegativity of bonding elements to find electronegativity of molecule

how to name ionic molecules

cation + anion + “ide”

if it is transition metal, add charge to the cation

how to name covalent compounds (not oxyanions)

prefix + element 1 + prefix + element 2 + “ide”

if first element has a prefix of “mono”, don’t say it

how to name oxyanions

base name + “ate”

• + 1 oxygen, add prefix “per”

• - 1 oxygen, add suffix “ite”

• - 2 oxygen, add prefix “hypo” and suffix “ite”

how to name binary acids

“hydro” + nonmetal + “ic” + “acid”

how to name oxyacids

• if ends with “ate”: anion + “ic" + “acid”

• if ends with “ite”: anion + “ous” + “acid”

electron configuration for cations

1. start from neutral electron configuration

2. remove highest n level first

3. remove p electrons before s electrons

4. transition metals: electrons go to d before s

exceptions for neutral electron configuration

Cr: 1 electron in each valance orbital

Cu: 1 electron in 4s orbital, electron is moved to fill all 3d orbitals

calculate wavelength from frequency

wavelength = c / f

find molarity

amt of solute (moles) / amt of solution (L)

dilution equation

M1V1 = M2V2

volume and pressure relationship

inversely proportional

volume and temperature relationship

directly proportional

volume and moles relationship

directly proportional

ideal gas law

PV=nRT

V = liters

P = atm

T = kelvin

n = moles

R = 0.08206 L*atm/mol*K

partial pressure equation

Ptotal = Pa + Pb + Pc …

Ptotal = (RT/V)(na + nb + nc …)

mole fraction equation

Pa / Ptotal = na / ntotal

root mean square velocity

M = √(3RT)/M

R = 8.314

T = kelvin

M = molar mass

rate of effusion

Ra / Rb = √(Mb / Ma)

R = rate of gas

M = mass of gas

heat capacity equation

q = C*∆T

C = J/°C

specific heat capacity

q = mc∆T

energy change of a reaction

∆H = ∆E + P∆V

what is standard state?

1 atm, 25°C

enthalpy of reaction

∆H° = ∆Hf°(products) - ∆Hf°(reactants)