CHEM 131 FINAL EXAM

Mass Number

# of protons + # of neutrons

Atomic Number

# of protons in the nucleus

Percent Yield

%yield= Actual/Theoretical * (100%)

Strong Electrolytes

=Strong acids and strong bases i.e. HCL and KOH

Weak Electrolytes

=all acidic and basic compounds that are not strong i.e. HF

Non-electrolytes

All molecular compounds that aren't acid/base

Ionic Radius

Cations (+)--smaller than their corresponding neutral atom Anions (-) -- larger than their corresponding neutral atom TREND- increases down a group

Density

D=m/v

Force

F=m*a

The Photoelectric Effect

If light is shined on a metal plate it kicks off the metal atoms; must be above a certain energy; intensity of light has no effect on the amount of e- kicked off

Exothermic

Negative enthalpy change (-H value) i.e. heating food in a bowl If heat flows OUT and q= - number

Law of Conservation of Mass

Neither created nor destroyed

Non-polar

No difference in electronegativity. Diatomic elements are non-polar

Endothermic

Positive enthalpy change (+H value) i.e. ice pack If heat flows IN and q=+number

Increase N:P Ratio

Positron emission, electron capture, and alpha emission

Empirical Formula

Strategy. 1. Assume you a had a 100g sample 2. Find mol of each element. 3. Divide ALL by the smallest # of mols found. 4. Multiply by a factor so all #'s are whole. (sometimes last step is unnecessary)

Electron Affinity (Eea)

TREND- irregular highest for halogens lowest for noble gases and alkaline earth metals

Ionization Energy (Ei)

TREND-Increases left to right across a period Decreases down a group

Covalent Bonding

Two atoms share e- equally between two non-metals

Mass Defect

a change in nucleon mass associated with proton/neutron binding

Solute

a chemical species which is dissolved in the solvent

Solvent

a liquid in which a chemical rxn is ran

Redox

a rxn in which electrons are transferred between two chemical species (changing the oxidation states)

Ionic Bonding

a transfer of e- from one atom to another Occur between a metal and a non-metal

Theoretical Yield

the max amount of product that can be made

Wavelength

wavelength=C/V C=2.997*10^8m/s

Paramagnetism

when there is unpaired e- it is most likely paramagnetic

Sig Figs Addition and Subtraction

can't have any more sigfigs to the right of the decimal, than the original number

Electroplating

depositing one metal on the surface of another using redox chemistry

Polar

difference in electronegativity

Law of Multiple Proportions

elements combine to form new compounds; these compounds contain elemental ratios that are small whole # ratios of one another

Lattice Energy

energy required to break the bonds in an ionic solid (measures the strength of a compound's ionic bonds)

Atomic Radii

half the distance between two identical nuclei TREND: Decreases across a period Increases down a group Decreases as Zeff increases

beta rays

highest form of energy output...1 element to the right DECREASE N:P Ratio

Soluability

how much of a solid will dissolve in a liquid

Dilution

process of preparing a less concentrated solution from a more concentrated one EQUATION: M1V1=M2V2

Specific Heat

q=mc(deltaT)

Positron emission

release of a positive electron.. add one electron

Eutrophication (FUN FACT)

release of nitrates and phosphates from fertilizer run-off

Law of Definite Proportions

samples of a pure compound will always have the same mass ratio of atoms

Precipitation

soluble ionic reactants combine to form an insoluble solid product

Sig Figs Multiply and Divide

the answer should have the least amount of sigfigs as used in part of the calculation

alpha rays

the ejection of an alpha particle from the decaying element (helium)... 2 elements to the left Atomic # increases by 2 Mass # decreases by 4

Electronegativity

ability of an atom to attract shared e- in a covalent bond TREND: Increase left to right across the period Increase up group

Resonance Structures

all forms of the compound possible to be drawn

Actual Yield

amount of product actually recovered

Neutralization

an acid (proton donor) reacts with a base (proton acceptor) to yield H2O and an ionic compound

Electron Capture

an electron absorbed.. take away one electron

Isotopic Abundance

atomic mass= (%abundance of X) (Isotopic Mass of X)