Studied by 1 personwhat types of elements are ionic compounds made of
metal and nonmetal
how do ionic compounds form
electrons are transferred from one atom to the other to form a cation and an anion that are attracted to each other with electrostatic attraction and form a giant crystal lattice of cations and anions with fixed electrons
formula for lead nitrate
Pb(NO3)2
formula for ammonium chloride
NH4Cl
formula for potassium hydrocarbonate
KHCO3
formula for copper (II) bromide
CuBr2
formula for chromium (III) sulfate
Cr2(SO4)3
Sn3(PO4)2
Tin phosphate
Hg2S
Mercury sulfide
what happens to the electron configurations of Mg and Br when they react to form the compound magnesium bromide
2 electrons transfer from magnesium to 2 bromide atoms to form a magnesium cation (Mg2+) and 2 bromide anions (2Br-) magnesium and bromide are attracted to each other through electrostatic attraction and form a giant crystal lattice Mg (1s22s22p63s2) Mg2+ (1s22s22p6) Br (1s22s22p63s23p64s23d104p5) Br- (1s22s22p63s23p64s23d104p6)
what charge do cations have
positive charged ion remember ca+ion
what charge does an anion have?
negatively charged ion
why do some atoms have multiple charges?
fully filled, empty, and half-filled electron sublevels are more stable than partially filled levels
what structure do ionic compounds form
a giant crystal lattice NO INDIVIDUAL MOLECULES
what structures do covalent compounds form
individual discrete molecules
how do covalent bonds form
electrons are shared between nonmetals - partially = polar - equally = non-polar
what electronegativity difference is a nonpolar covalent
0.0-0.4 electronegativity difference
what electronegativity difference is polar covalent
0.4-2.1 electronegativity difference
what electronegativity difference is ionic
2.1-4.0 electronegativity
what are the physical properties of metals
malleable, ductile, conductors of electricity and heat, lustrous, alloys
why are metals malleable
electrons are free-moving in the crystal lattice of cations which means with enough force the cations can be forced to slide past each other
what kinds of ions are metals
cations
why are metals ductile
metals have free moving e- with fixed cations, which menas with enough force the crystal lattics of fixed cations can be forced to move past one another, stretching metal into wires
why are metals lustrous
metals have fixed cations with free moving e- when photons are shined on metals they do not penetrate fully throughout the structure and instead are bounced off of the free/delocalized e-
what is the movement of electrons in metals
electrons are delocalized, free moving
why are metals good conductors of electricity
metals always have moving charges, from the delocalized e- therefore these moving charges can be induced into moving a specific direction with an applied charge, inducting electricity
why are metals good conductors of heat
metals have delocalized e- that do not require large amounts of energy to move them more within the structure
what is heat
total kinetic energy
what is temperature
average kinetic energy
are ionic compounds (s) good conductors of electricity
no. solid ionic compounds are fixed in a giant crystal lattice which means that the localized electrons are not abel to be induced into moving a specific way
are covalent compounds good conductors of electricity
no. all phases of matter of covalent compounds cannot conduct electricity because they have no charges
what is the electrical conductivity of (aq)/(l) ionic compounds
can conduct in aqueous or liquid state because the giant crystal lattice is broken and the e- are no longer localized
can covalent compounds conduct heat
covalent compounds have weak intramolecular forces that cause the e- to be localized, covalent compounds do not require a lot of energy to break these intramolecular forces, which is why tehy have low melting and boiling points
what types of compounds have high mp/bp
metalllic and ionic
what types of compounds have low mp/bp
covalent compounds
how do melting points of metals change going across a period
melting point of metals go up
explain the trend in melting points going from Titanium to Cobalt
melting point increases - metallic bonding strength increases BECAUSE - #ve- and the charge of cations increases - radius decreases
how does the melting point of metals change going down a group
melting point goes down
explain the trend of melting points from Berylium to Barium
melting point decreases - metallic bonding strength decreases BECAUSE - cation radius increases down the table - increased shielding effect - greater distance between the ve- and cation -> weaker attraction to ve- -> weaker metallic bond
which atoms are most likely to form covalent bonds
nonmetal atoms that share e-
how does bond length change compared to bond strength
as number of bonds increases bond strength increases and length decreases BECAUSE the nuber of shared electron pairs increases
what is the octet rule
an atom must have 8 ve- to satisfy its valence shell
which flouride is the most ionic.Why? A. NaF B. CsF C. MgF2 D. BaF2
CsF, Cesium flouride because Cs and F have the highest electronegativity difference. Cs is the metal the lowest electronegativity and F with the highest electronegativity higher electronegativity difference means that it is more ionic
which pair of elements reacts most readily A. Li + Br2 B. Li + Cl2 C. K + Br2 D. K + Cl2
D. K + Cl2 The electronegativity difference between potassium and chloride is the highest
you are given two white solids and one is an ionic compound. describe 3 tests to perform to determine which is ionic. explain.
try conducting electricity (ionic compounds as solids are unable to conduct electricity, the one that acts as an insulator as a solid is the ionic compound) try heating and melting (ionic compounds have high mp/bp, so it would be more difficult ot melt/boil) test solubility in water (ionic compounds have ions that are attracted to each other with electrostatic attraction that are attracted to the partial charges of water H2O)
Which of the following bonds contains the shortest bond between carbon and oxygen? A. CO2 B. H3COCH3 C. CO D. CH3COOH
carbon monoxide. carbon and oxygen has a triple bond between them
predict the bonds of C - H C - Cl which is more polar? (Table 8 of data booklet)
electronegativity difference between C - H = 2.6-2.2 = 0.4 nonpolar/polar (in between) electronegativity difference between C - Cl = 3.2-2.6 = 0.6 polar C - Cl is more polar
how do you determine the molecular geometry?
from molecular formulas
VSEPR Theory
pairs of e- orient themselves as far apart as possible from each other
2 electron clouds
edg = linear mg = linear angle = 180
3 bonding e- clouds
edg = trigonal planar mg = trigonal planar angle = 120
2 bonding 1 nonbonding
edg = trigonal planar mg = bent/v-shaped angle = <120
why are some bonding angles not exact and less than a defined angle?
because the nonbonding pairs of electrons make the exact electron domain geometry difficult to determine as they continue to move
4 bonding electron clouds
edg = tetrahedral mg = tetrahedral angle = 109.5
3 bonding 1 nonbonding
edg = tetrahedral mg = trigonal pyramidal angle = <109.5
2 bonding 2 nonbonding
edg = tetrahedral mg = bent/v-shaped angle = <109.5 (less than iif it was 3 bonding and 1 nonbonding)
saturated hydrocarbon
hydrogen and carbon connected with only single bonds
how many bonds can carbon have
4
1C alkane
methane CH3
2C alkane
ethane CH3CH3
3C alkane
propane CH3CH2CH3
4C alkane
butane CH3CH2CH2CH3
5C, 6C, 7C, 8C, 9C, 10C, alkane
pent-, hex-, hept-, oct-, non-, dec-, ane
characteristics of alkanes
generally inert (not reactive) why? the strength and stability of C-C bond, bond enthalpy is very high - nonpolar
empirical formula for alkanes
CnH2n+2
empirical formula for nonane
C9H20
condensed formula for nonane
CH3CH2CH2CH2CH2CH2CH2CH2CH3
parent chain of a branched hydrocarbons/organic structures
"longest 'chain'/line of carbons"
substituents
branches off the parent chain
naming branched alkanes
3,4 - dimethylheptane 3,4 : location of the methane substituents di : 2 methane substituents heptane : parent 8C alkane
isomer
compounds with the same molecular formula and different structure
writing the condensed formula for organic compounds
CH3CH2(CH2CH3)CHCH2CH2CH3 2-ethylhexane CH3CH2(CH2CH3)CHCH2CH2CH3 - 2-ethane CH3CH2(CH2CH3)CHCH2CH2CH3 - hexane
unsaturated hydrocarbon
a molecule of hydrogen and carbon containing 2+ bonds
alkene
hydrocarbons with double bonds C2H2n
alkyne
hydrocarbons with triple bonds CnH2n-2
naming alkenes and alkynes
identify the longest chain of consecutive carbons locate the double bond, and number chain so the double bond is the lowest numberlocate and number the substituents
identify the construction of 2-methylhepta-1,5-diene
CH2CH(CH3)CH2CH2CHCHCH3 2-methylhepta-1,5-diene
properties of hydrocarbons
non-polar - only betwen C & H London dispersion forces - forces stronger with greater mass - forces weather with more branching
how do london dispersion forces change
becomes stronger with greater mass becomes weaker with branching
how does boiling point of hydrocarbons change
decreases with increased branching becuase the london dispersion forces become weaker and it is easier for heat (energy) to break the london disperion forces between molecules
homologous series
differ by a CH2 - physical properties: MP/BP increases as the mass increases (mass increases as number of carbons increases) - chemical properties: homologous series will have similar chemical properties due to similar types of bonds (but depends on the types of bonds)
complete combustion of hydrocarbons
CxHy +O2 (g) - > CO2(g) + H2O (g) + Energy
type of reaction of combustion of hydrocarbons
exothermic, releases energy
what state of matter when number of carbons 4 </=
CxHy - gas
what state of matter when number of carbons 5 >/=
CxHy - liquid
CxHy - liquid
what state of matter when number of carbons 5 >/=
how does incomplete combustion of hydrocarbons occur?
when there is insufficient oxygen O2
products of incomplete combustion of hydrocarbons
soot, carbon monoxide
what is the hazard of products of incomplete combustion of hydrocarbons
carbon monoxide - odorless, poisonous, results in carbon monoxide poisoning soot - can cause lung damage
functional group
site of reactivity in a molecule - an atom or group of atoms
class
= type or family of compounds containing a specific functional group
alkanes, alkenes, alkynes, arene type of bonding (with only C and H)
non-polar covalent
alkanes, alkenes, alkynes, arene type of IMF (with only C and H)
London Dispersion Forces ONLY
alkanes, alkenes, alkynes, arene physical properties (with only C and H)
very volatile (can evaporate easily) high vapor pressure insoluable in water neutral
alkene functional group
alkenyl, contains double bonds between carbons
alkynes functional group
alkynyl, contains triple bonds between carbons
arene functional group
phenyl, contains C6H5 (benzene) cyclic structure
halogenoalkanes/alkylhalides (class), halogeno (functional group)
contains halogens
halogenoalkanes/alkylhalides (class), halogeno (functional group) structure
C - X X = halogen
halogenoalkanes/alkylhalides (class), halogeno (functional group) type of bonding
polar covalent
Note
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