CHEM 120 Final (Theory Only) - 1a 2025

How many unique elements are there?

118

How many unique chemical substances exist?

204 million

What are transition metals?

d block elements with high melting points

What are alkali metals and their properties?

Column 1 - soft, highly reactive, shiny metals

What are noble gases and their properties?

Column 18 - colorless/odorless with low reactivity

What are actinoids?

Bottom row of f block - radioactive metallic elements

What are alkaline earth metals?

Column 2 - shiny, reactive metals

What are lanthanoids?

Top row of f block

What are halogens?

Column 17 - salt producing nonmetals

What is a synthesis reaction?

Two or more reactants form new products

What is a decomposition reaction?

One reactant breaks into two or more products

What is a single displacement reaction?

One element is replaced by another more reactive element

What is a double displacement reaction?

Positive and negative ions replace each other

What is a combustion reaction?

Compound reacting with O2 forms CO2 and H2O

What is an acid-base reaction?

Proton is transferred to base from acid

What are properties of ionic compounds?

Solids at room temperature, have positive and negative ions, most dissolve in water with hydration sphere

What is the formula for hydronium?

H3O+

What is the formula for hydroxide?

OH-

What is the formula for ammonium?

NH4+

What is the formula for nitrate?

NO3-

What is the formula for nitrite?

NO2-

What is the formula for cyanide?

CN-

What is the formula for cyanate?

CNO-

What is the formula for thiocyanate?

SCN-

What is the formula for formate?

HCO2-

What is the formula for hydrogen sulfate?

HSO4-

What is the formula for sulfate?

SO4^2-

What is the formula for phosphate?

PO4^3-

What is the formula for hydrogen phosphate?

HPO4^2-

What is the formula for hydrogen diphosphate?

H2PO4-

What is the formula for phosphite?

PO3^3-

What is the formula for carbonate?

CO3^2-

What is the formula for hydrogen carbonate?

HCO3-

What is the formula for peroxide?

O2^2-

What is the formula for acetate?

C2H3O2-

What is the formula for perchlorate?

ClO4-

What is the formula for chlorate?

ClO3-

What is the formula for chlorite?

ClO2-

What is the formula for hypochlorite?

ClO-

What is the formula for chromate?

CrO4^2-

What is the formula for dichromate?

Cr2O7^2-

What is the formula for permanganate?

MnO4-

What are properties of molecular compounds?

Stable neutral molecules, solid/liquid/gas, become hydrated when dissolved in water, generally don't have metals

What are the steps of a precipitation reaction?

1) Two solutions with ionic species are mixed 2) Insoluble compound forms 3) Isolate by filtering

What is solubility rule 1?

Salts of alkali metals are soluble

What is solubility rule 2?

Ammonium salts are soluble

What is solubility rule 3?

Nitrates are soluble

What is solubility rule 4?

Chlorides, bromides and iodides are soluble except with lead, mercury, and silver

What is solubility rule 5?

Sulfates are soluble except with calcium, strontium, barium, silver, mercury and lead

What is solubility rule 6?

Carbonates, phosphates and sulfides are insoluble unless trumped by rule 1 or 2

What is solubility rule 7?

Hydroxides are insoluble or slightly soluble unless trumped by rule 1

What is a molecular equation?

Standard way to write a chemical equation

What is a full ionic equation?

All ions are separately written out except for those that are insoluble

What is a net ionic equation?

Crosses out all ions appearing on both sides, leaving only the ions that form the precipitate

What are the common strong binary acids?

HCl (hydrochloric), HBr (hydrobromic), HI (hydroiodic)

What are the common strong oxo acids?

HClO4 (perchloric), HBrO4 (perbromic), HIO4 (periodic), HNO3 (nitric), H2SO4 (sulfuric)

What are common strong bases?

Group 1 hydroxides (LiOH, NaOH, KOH) and Group 2 hydroxides (Mg(OH)2, Ca(OH)2, Sr(OH)2)

What is the Bronsted-Lowry definition of acids and bases?

Acid is a proton (H+) donor and a base is the acceptor

What is acid-base neutralization?

An acid and a base react to form a salt and often water

When does neutralization go to 100% completion?

If either the acid or base is strong

What is the formula for number of moles?

n = m/M

What is the formula for density of pure liquids?

ρ = m/V

What is the formula for concentration?

C = n/V

What is theoretical yield?

Maximum amount of product you can produce

What is the formula for percent yield?

% yield = (actual yield/theoretical yield) × 100

What is a consecutive reaction?

The product of one reaction is the reactant for the next

What is an intermediate in consecutive reactions?

Product that becomes reactant; never appears in overall reaction

What are simultaneous reactions?

Independent reactions that occur at the same time

What is the formula for percent atom economy?

(Stoichiometric mass of desired product / mass of stoichiometric mixture of reactants) × 100

What does high atom economy indicate?

Better green chemistry - more reactants incorporated into product

What is the E factor formula?

Mass of waste produced (excluding water) / mass of product obtained

What does a low E factor indicate?

Better green chemistry - less waste produced

What is quantum theory?

When an electron is confined to a finite region of space by forces, its total energy is restricted to special values

What is light?

Electromagnetic radiation with magnetic and electric fields oscillating perpendicular to each other

What is the relationship between wavelength, frequency, and speed of light?

λ (wavelength) × ν (frequency) = c (speed of light)

What is the order of the electromagnetic spectrum from shortest to longest wavelength?

γ-rays, X-rays, ultraviolet, visible (400-750nm), infrared, microwaves, radio waves

What is the relationship between wavelength and energy?

Shorter wavelengths have higher energy; longer wavelengths have lower energy

What did the black body radiation experiment show?

Heated atoms only oscillate in certain energies: E_osc = nhν

What is the photoelectric effect?

Light energy is highly localized and proportional to its frequency

What is the formula for photon energy?

Ephoton = hν OR Ephoton = hc/λ OR E_photon = w + KE

When is the photoelectric effect observed?

When E_photon > w (threshold energy)

What do line spectra of atoms show?

Energy of an electron is restricted to certain values

What is Bohr's energy level formula?

E = -(R_H/n²)

What is the Bohr radius?

52.9 pm

How does energy change as n increases in Bohr's model?

Energy increases (becomes less negative) as n increases

What does positive ΔE mean in energy level transitions?

Electron went from low to high energy level

What does negative ΔE mean in energy level transitions?

Electron went from high to low energy level

What are problems with Bohr's model?

Doesn't explain quantization, not extendable to other atoms, doesn't explain lack of continuous radiation

What is De Broglie's hypothesis?

Light exhibits wave-particle duality

What is the relationship between mass and De Broglie wavelength?

As mass increases, De Broglie wavelength decreases

What is Heisenberg's uncertainty principle?

Impossible to simultaneously know both position and momentum of a particle with absolute certainty

What does ψ² represent if electron is a particle?

Probability of finding electron within a region of volume near nucleus

What does ψ² represent if electron is a wave?

Density of electron cloud within region of volume near nucleus

What does quantum number n represent?

Size/energy level of orbital

What does quantum number l represent?

Shape of orbital (0=s, 1=p, 2=d)

What does quantum number m_l represent?

How many kinds of orbital there are (n-1)

What does quantum number s represent?

Spin (+½ = spin up, -½ = spin down)

What is the general rule for number of orbitals?

Number of orbitals = n²

What is the formula for radial nodes?

Radial nodes = n - l - 1

What is the formula for angular nodes?

Angular nodes = l