Chem 1A midterm 1

chemistry

the study of matter and the changes it undergoes

for Li what is the atomic mass and atomic number

atomic number 3, atomic mass 6.94

properties of matter

solid, hard, shiny, squishy, flexible, liquid, wet, soft, blue, sweet

bonding ratios increase

left to right

reactivity increases

Top to Bottom (Metals) Bottom to top (Non Metals)

mass increases

left to right and top to bottom

radius increases

right to left and top to bottom

hardness increases

bottom to top (metals)

nonmetals

H, C, P, Se, I, At and everything to the right

metalloids

B, Si, Ge, As, Sb, Te

model

conceptual or mathematical representation of real-workd things or processes; simplier than the real thing, Does NOt have to be perfectly accurate, DOES have to align with current and future data

elements

unique # of protons (Z)

protons where, charge, size, mass?

in nucleus, 1+, big relatively, ~1 amu

neutrons where, charge, size, mass?

nucleus, none, big, ~1 amu

electrons

where, charge, size, mass?

in shells outside the nucleus, 1-, tiny, ~0amu

isotopes

unique # of neutrons (same element just different amnts of neutrons)

average atomic mass =

weighted average of isotope masses

ions

unequal # of protons and electrons (ex. same element; same amnt protons diff electron amnt)

cation

# protons > # electrons (+ charge overall); metals atoms "give up" valence e- to become ions with net (+) charge

anion

# protons < # electrons (- charge overall); nonmetals "steal" valence e- to become ions with net (-) charge

core electrons

e- in inner shell(s)

valence electrons

e- in outermost shell

Coulomb's Law what is each variable (should be on equation sheet) F=k[(q1q2)/(r^2)]

F= force -attract +repel k=constant, q1q2=charges r^2=distance b/w charges

opposite charges _______, like charges __________, bigger/greater charges=_______, bigger/greater distance=______

ATTRACT, REPEL, stronger force/attraction, weaker force/attraction

radius reactivity and softness increases

down a column same across a row

core e- in inner shells ________, valence e- __________-

repel, outward

z effective=

protons - core e

higher z eff means

stronger hold on outer electrons=higher ionization and greater electronegativity

protons on element

atomic number

neutrons on element

mass # - atomic#

electrons are the ________ that ___________ atoms ________

glue, hold, together

metallic bonding

exists in substance consisting only of metallic elements, such as Al(s) and Cu(s)

molecular covalent bonding

exists in substances consisting only of nonmetal elements, such as H20, sugar, alc, acetone

ionic bonding

exists in substances consisting of metal + nonmetal elements, such as NaCL, NaHCO3, and FeSO4

extended covalent bonding

exists in substances consisting only of nonmetal elements, such as C(s) and [CH2]n

solubility for the bondings

more electron glue=

metallic=

molecular covalent=

ionic=

extended covalent=

more electron glue=less soluable

metallic= doesnt dissolve

molecular covalent= many dissolve

ionic=many dissolve

extended covalent= doesn't dissolve

Conductivity for bondings

more mobile charges=

metallic=

molecular covalent=

ionic=

extended covalent=

more mobile charges=more conductive

metallic= conducts dry

molecular covalent= doesnt conduct

ionic= solution conducts

extended covalent= doesn't conduct

hardness in bonding

more electron glue=

more mobile electrons

metallic

molecular covalent

ionic

extended covalent

more electron glue=stronger bonds

more mobile electrons=more bendable bonds

metallic=bendable, malleable

molecular covalent=gases, liquids, or soft solids

ionic=hard, but brittle

extended covalent= rigid, difficult to break

ionic brittleness

charges too close, ionic solids break, snap, or crack

metallic bonding patterns for hardness, conductivity, and solubility

hard/flexible, insoluble, conducts dry

molecular covalent bonding patterns for hardness, conductivity, and solubility

soft/liquid/gas, osluble, doesn't conduct

ionic bonding patterns for hardness, conductivity, and solubility

hard/brittle, soluble, solution conducts

extended covalent/network covalent bonding patterns for hardness, conductivity, and solubility

hard, insoluble, doesn't conduct

subscripts shows

how many of the thing right before it

superscripts show

charge

isomers

lewis structures with atoms connected differently; same molecular formula, different structural formula

Resonance Contributors

same atom locations, different e- locations

finding bond orders

counting the lone and base pairs and getting the average

changing temps: temps vs avrg KE(kJ/mol)

directly proportional

changing temps: temps vs avrg v(m/s)

v generally increases with T; inversely proportional

other impacts of temp: temps vs volume(L)

directly proportional

other impacts of temp: temps vs pressure (atm)

directly proportional; P=kT P=collisions with walls (in rigid container)

changing volume and pressure: volume (L) vs pressure (atm)

inversely proportional

__________ containers will change V until P inside=P outside

flexible

Equalizing Pressure: volume (L) vs pressure (atm)

inversely proportional

changing # of particles: # of particles(mol) vs pressure(atm)

directly proportional (rigid container)

changing # of particles: # of particles (mol) vs volume (L)

directly proportional (flexible container)

Ideal gases

no interactions; only motions (KE)

Real gases

motion (KE) & interactions (PE)

Real Gases: Compression

high V: Preal = Pideal because particles are too far apart to experience attractions (KE wins!)

low V: Preal < Pideal because attractions keep particles closer together and less likely to collide with the walls (PE wins!)

Real Gas Law: {P+ a[(n^2)/(V^2)]} x (V - nb) = nRT what's a and b?

a is accounts for attraction; b is accounts for "bigness"

Real Gases: Cooling

high T: Vreal = Videal

because high kinetic energy outweighs potential energy

med T: Vreal < Videal

because attractions keep particles closer together

low T: Vreal > Videal

because particles have some nonzero size

in liquids/low T

PE wins; favors the attractions of liquids

in gas/ high T

KE wins; favors the motions of gases

Kinetic energy

more important at high T; ideal gas-like behavior

potential energy

more important at low T; real gas or liquid-like behavior

formal charge formula

# valence e when alone - #nonbonding e - # bonds

formal charge readings

Better structures have fewer and smaller formal charges. the negative formal charge on the more electronegative atom

what is the geometry shape, domain, bond pairs, and bond angle

linear; 2 domains; 2 bond pairs; 180

what is the geometry shape, domain, bond pairs, and bond angle

trigonal planar; 3 domains; 3 bond pairs; 120

what is the geometry shape, domain, bond pairs, and bond angle

bent; domains vary, 2 bond pairs; less than 180

what is the geometry shape, domain, bond pairs, and bond angle

tetrahedral; 4 domains; 4 bond pairs; 109.5

what is the shape, domain, bond pairs, and bond angle

trigonal pyramidal; 4 domains; 3 bond pairs; 107.5

what is the shape and bond angle

trigonal bipyramidal; 120 and 90

electron domains

Regions of electron density around a central atom.

molecular geometry vs electron geomtery

molecular: w/out lone pairs electron: with lone pairs

nonpolar covalent

equal sharing ex. F-F

polar covalent

unequal sharing ex. F-H

ionic polarity

electron transferred

electronegativity

the intrinsic ability of an atom to attract a bonding pair of electrons towards itself

electronegativty increases from

left to right bottom to top

hydrogen bonding

polar molecules that has a N, O, or F bonded to a Hydrogen; attraction that forms due to different charges; not a bond because electrons are not being transferred

ion ion

the attractions or repulsion between two fully charged particles(ions); opposites charges attract ex NaCl

ion dipole

attraction between a fully charged ion (NaCL when breaking)(+ or -) and a partially charged side of a polar molecule(H2O)(𝛿+ or δ−)

dipole dipole

when polar molecular that produces 2 regions of opposite charges like partial - attracts to partial + (ex. HCl)

D-ID

when a regular/permanent dipole(H2O) (balanced and not lopsided) molecule gets attracted to a lopsided molecule/induced dipole(O2)

London Dispersion Forces or (ID-ID)

persent in ALL molecules, only IMF present in nonpolar moleculars; like dipole dipole but it’s a temporary dipole

IMF strength from strongest to weakest

Ion-ion > Ion-dipole > Hydrogen bond > Dipole-dipole > Dipole-induced dipole > Induced dipole-induced dipole