IB Chemistry SL Topics 4 and 10 Test Review

what 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 =

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 =

2 bonding 2 nonbonding

edg = tetrahedral mg = bent/v-shaped angle =

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