Chem study guide exam 1 PDF PDF

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everything you need to know for exam 1
learning objectives for chapters 1-3
Carpenter...

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CHEM%STUDY%GUIDE%EXAM%1% % Chapter(1( % Distinguish)between)a)hypothesis)and)a)law)or)theory:) Hypothesis-%an%explanation%for%why%or%how%something%happens%that%can%be%tested%to% eventually%form%a%theory%or%a%law% Law-%a%statement%that%explains%a%relationship%between%phenomena% Theory-%a%principle%that%unifies%many%observations%and%is%the%basis%for%laws% % Distinguish)between)a)substance)and)a)mixture:) Substance-(matter%with%constant%composition%and%distinct%properties,%can%be%solid,%liquid,% or%gas% % Ex.%Water,%salt,%mercury% Mixture-%a%combination%of%substances%that%can%be%separated%without%any%chemical% reactions% % Homogeneous(mixture-%mixture%with%uniform%composition% % % Ex.%Salt%water%% Heterogeneous(mixture-%mixture%with%non-uniform%composition% % Ex.%Sand%and%iron%chips% % Explain)the)difference)between)a)solid,)liquid)and)gas:) Solid-%Particles%held%close%together,%constant%shape%and%volume% Liquid-%Particles%held%close%together%but%not%as%rigidly%as%in%solids,%constant%volume% Gas-%Particles%are%free!% % Distinguish)between)a)physical)and)chemical)process)or)change:) Physical(process-%does%not%change%identity%of%substances% Chemical(process-%identity%of%substances%change% % PROPERTIES% Distinguish)between)a)physical)and)chemical)property:) Physical(property-%Can%be%observed%and%measured%without%changing%the%chemical% property%of%the%substance% Chemical(property-%You%have%to%change%the%chemical%property%to%observe%it% % Distinguish)between)a)quantitative)and)qualitative)property:) Quantitative(property-%Properties%described%using%numbers% Qualitative(property-%Properties%described%using%words%or%categories% % Distinguish)between)an)extensive)and)intensive)property:) Extensive(property-%property%depends%on%the%amount%of%matter% % Ex.%Mass,%volume% Intensive(property-%property%does%not%depend%on%the%amount%of%matter% % Ex.%density% %

Identify)the)SI)base)units:) % Base(Quantity( Name(of(Unit( Symbol( Length% Meter% m% Mass% Kilogram% kg% Time% Second% s% Electric%current% Ampere% A% Temperature% Kelvin% K% Amount%of%Substance% Mole% mol% Luminous%intensity% Candela% cd% % Note:%Atomic%mass%is%measured%in%amu% % Metric%prefixes:% Prefix( Symbol( Meaning( Tera% T% 1x1012% Giga% G% 1x109% Mega% M% 1x106% Kilo% k% 1x103% Deci% d% 1x10-1% Centi% c% 1x10-2% Milli% m% 1x10-3% Micro% 1x10-6% µ% Nano% 1x10-9% h% Pico% p% 1x10-12% % % Conversion(factors( ( h%=%6.626%x%10-34%J⋅s% 1%inch%=%2.54%cm% c=3.00x108%m/s% 1%mile%=%5,280%feet% 1%foot%=%12%inches% 1%calorie%=%4.184%joules%(J)% 1%yard%=%3%feet% 1%atmosphere%=%760%torr%=%760%mm%Hg% -10 1%angstrom%(A^ )%=%10 %m% 1%atm%=%101,325%Pa% R%=%0.08206%atm⋅L/mol⋅K% 1%pound%=%16%ounces% 1%mole%=%6.02%x%1023%units% % Convert)temperatures)between)Celcius)and)kelvin:) K(=(°C(+(273.15( Density-%ratio%of%mass%to%volume% 𝑚𝑎𝑠𝑠 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 = % 𝑣𝑜𝑙𝑢𝑚𝑒 % % %

Identify)the)number)of)significant)figures)in)a)given)number)or)measurement:) • All%non-zero%digits% • All%zeroes%between%non-zero%digits% • All%zeroes%after%non-zero%digit% • No%zeroes%before%first%non-zero%digit% % Express)numbers)in)scientific)notation:) 100%=%102% % Apply)significant)figure)rules)in)calculations)with)measured)numbers:) • Addition/subtraction-%smallest%number%of%sigfigs%after%decimal%point% • Multiplication/division-%smallest%number%of%sigfigs% % Distinguish)between)accuracy)and)precision:) Accuracy-%how%close%measurement%is%to%true%value% Precision-%how%often%you%get%the%same%measurement% % Conversion(factor-%fraction%of%that%contains%two%equivalent%measurements%or%values%which% lets%us%convert%measurements%to%new%units% % Recall%metric%prefixes-%above% % Select(correct(conversion(factors-%always%make%sure%to%cancel%out%units%by%putting%the% new%unit%in%the%numerator%of%the%fraction%and%putting%the%old%unit%in%the%denominator% (assuming%the%old%unit%was%in%the%numerator%for%the%initial%measurement% % Use%conversion%factors%correctly%in%dimensional%analysis-%see%above% % Demonstrate%the%conversion%of%squared%or%cubed%units-%% • If%you%are%going%from%m%to%m3,%make%sure%you%cube%the%WHOLE%value% Ex.%% 5 1000𝑐𝑚5 1 ∗ 1067 𝑚 3𝐿 ∗ ∗ = 3 ∗ 1065 𝑚5 % 1𝐿 1𝑐𝑚 Apply%derived%units%in%dimensional%analysis:%% We%were%able%to%convert%3%L%to%its%equivalent%in%m3% % ( ( ( ( ( ( ( ( (

Chapter(2( % Mass(Number((A)-%total%number%of%neutrons%and% Particle% Charge% Charge% protons%in%atom%(except%hydrogen)% unit% Atomic(Number((Z)-%Number%of%protons%in%the%nucleus% Electron% -1.6022%x%10-19% -1% Average(atomic(mass-%The%average%mass%of%all%of%the% Proton% 1.6022%x%10-19% +1% isotopes%of%that%element,%considering%the%different% 0% frequencies%of%those%isotopes%(number%on%periodic%table)% Neutron% 0% % Determine)the)number)of)electrons,)protons)and)neutrons)for)a)given)atom) • Protons%=%atomic%number% • Electrons%=%atomic%number% • Neutrons%=%mass%number%–%atomic%number% % Table%2.2% Protons% Neutrons% Number%of%stable%Isotopes% Odd% Odd% 4% Odd% Even% 50% Even% Odd% 53% Even% Even% 164% %% Nucleus%stability% • Nuclei%that%contain%2,%8,%20,%50,%82,%and%126%protons%or%neutrons%are%generally%more% stable%than%other%nuclei.%(magic%numbers)% • Nuclei%with%even%numbers%of%both%neutrons%and%protons%are%generally%more%stable.%% • Determined%by%neutron-%to-%proton%ratio%(n/p)% • Elements%with%low%atomic%numbers-%n/p%is%close%to%1% • As%atomic%number%increases,%n/p%ratio%of%stable%nuclei%increase%because%more% neutrons%are%needed%to%stabilize%repulsion%among%the%protons%in%nucleus.% • Elements)where)Z)>)83)are)radioactive) % Isotope-%naturally%occurring%versions%of%an%element%with%different%amounts%of%neutrons% % Average(atomic(mass%of%naturally%mixture%of%isotopes%=%(Frequency%of%isotope%1%)%x%(mass% of%isotope%1)%+%(Frequency%of%isotope%2)%x%(mass%of%isotope%2)%+….%% % Period-%across% Group-%columns,%similar%properties% Label%the%elements%which%are%metals,%nonmetals%and% metalloids%on%the%periodic%table% Label%the%alkali%metals,%alkaline%earth%metals,%halogens,% noble%gases%and%transition%metals%on%the%periodic%table% % % Elements%become%more%metallic%as%we%go%down%groups% and%less%metallic%as%we%go%from%left%to%right.%

Mole-%The%amount%of%a%substance%that%equals%the%same%amount%of%atoms%as%there%are%in%12g% of%carbon-12% Avogadro’s(number-%The%number%of%atoms%in%12g%of%carbon-12%and%the%number%of%atoms% that%are%in%a%mole%of%a%certain%substance% 6.022(x(1023( % Molar(mass-%the%mass%in%grams%of%one%mole%of%a%substance% % Apply%the%mole,%Avogadro’s%number%and%molar%mass%as%conversion%factors% ex.%How%many%atoms%are%in%50g%of%carbon?% 1:𝑚𝑜𝑙:𝐶 6.022×1075 𝑎𝑡𝑜𝑚𝑠 =:? ?% 50𝑔:𝐶 ∗ : ∗ 1:𝑚𝑜𝑙:𝐶 12.01𝑔:𝐶 % % % Chapter(3( % 𝟏 Kinetic(energy-%the%energy%that%comes%from%motion:( 𝑲𝑬 = 𝒎𝝊𝟐 % 𝟐 % % Wavelength% Frequency% Radiation% Gamma% X% Ultraviolet% Visible% Infrared% Microwave% Radiowaves% rays% rays% % Wavelength-%distance%between%identical%points%between%waves% Frequency-%number%of%waves%that%pass%through%a%point%in%1%second% % Relate)wavelength)to)frequency)using)the)speed)of)light:) 𝒄 = 𝟑. 𝟎×𝟏𝟎𝟖 :𝒎/𝒔 = 𝝀𝝊( Photon-%a%particle%of%light% Calculate)the)energy)of)a)photon:) 𝐸OPQRQS = ℎ𝑣% % Emission(spectra-%white%light%emitted%by%energy% Line(spectra-%emission%of%light%at%certain%wavelengths% % Ground(state-%lowest%energy%level%of%an%atom% Excited(state-%any%other%energy%level%of%an%atom% % When%an%atom%absorbs%radiant%energy,%electrons%move%from%the%ground%state%to%an%excited% state.%When%an%atom%emits%this%energy%the%electrons%go%back%to%the%ground%state.%% %

Use%equation%3.8% ∆𝐸 = ℎ𝑣 = −2.18:×:106XY 𝐽:

1 1 − 7 % 7 𝑛[ 𝑛\

% Note:%we%can%calculate%the%wavelength%of%matter% ) Bohr’s(model:%An%atom%consists%of%a%nucleus%filled%with%protons%and%neutrons.%Electrons% circle%around%the%nucleus%at%different%energy%states%depending%on%if%they%receive%light% signals%or%not.%% % Heisenberg(uncertainty(principle:%It%is%impossible%to%know%simultaneously%both% the%momentum)p%%(m%×%u)%and%the%position)x%of%a%particle%with%at%the%same%time%with% certainty.% % Quantum(numbers%place%electrons%in%different%places%of%the%atom,%starting%more%generally% and%becoming%more%specific,%like%the%different%numbers%on%a%ballgame%ticket.%The%quantum% numbers%ensure%that%no%two%electrons%occupy%the%exact%same%orbital%with%the%same%spin.%% % n-)describes%the%energy%level%(1,2,3,4,..)% l-)describes%the%subshell%(s,p,d,f)% ml-%describes%the%orbital% % The%orbital%is%in%the%subshell%which%is%in%the%energy%level.%Different%energy%levels%have% different%numbers%of%subshells.%Each%subshell%holds%a%specific%number%of%orbitals.%Each% orbital%holds%2%electrons.%% % Electron(spin(quantum(number,(ms)-electrons%in%an%orbital%must%have%opposite%spin,%+1/2% or%-1/2.%The%spin%number%is%one%of%these%2%values.%) % Describe%the%shape%of%s%and)p%orbitals:%S%is%spherical%and%p%looks%like%an%infinity%sign% % Show%how%the%number%of%orbitals%can%be%determined%at%the%shell%and%subshell%level% Each%shell%(n)%allows%for%(n-1)%subshells%(l).%% % Energy%level%(n)% Subshell%(l)% Orbital%(ml)% Spin% 1% 0% s% 0% -1/2,%+1/2% 2% 0,1% sp% 0,%-1,0,1% -1/2,%+1/2% 3% 0,1,2% spd% 0,%-1,0,1%,%-2,-1,0,1,2% -1/2,%+1/2% 4% 0,1,2,3% spdf% 0,%-1,0,1%,%-2,-1,0,1,2,%%-3,-2,%-1,0,1,2,3% -1/2,%+1/2% % Arrange%subshells%in%order%of%energy%level%(Aufbau(principle)%using%the%periodic%table% • You%can%order%subshells%in%order%of%energy%levels%by%drawing%boxes%for%the%amount% of%orbitals%in%each%subshell%and%filling%them%up%with%electrons%according%to%the% following%prinicples.%%

Apply%the%Pauli(exclusion(principle%to%electron%orbital%diagrams% • No%two%electrons%can%have%the%same%4%quantum%numbers,%so%when%you%fill%electron% orbital%diagrams,%no%two%arrows%in%one%box%can%face%the%same%direction% Degenerate(orbitals-%when%all%of%the%orbitals%in%the%subshell%are%filled%so%each%electron%has% the%same%chance%of%being%in%any%one%of%those%orbitals% Apply%Hund’s(rule%to%electron%orbital%diagrams% • When%filling%out%an%orbital%diagram,%start%by%filling%each%orbital%with%one%electron,% and%each%electron%should%have%the%same%spin% • This%is%the%most%stable%configuration% • Once%you%have%filled%each%with%one%electron,%start%adding%electrons%to%each%orbital%in% the%opposite%direction% Relate%electron%orbital%diagrams%and%electron%configurations% • For%each%s%subshell,%there%should%be%1%box%with%2%electrons%in%it% • For%each%p%subshell,%there%should%be%3%boxes%holding%6%electrons% Determine%if%an%element%is%paramagnetic%or%diamagnetic% Diamagnetic-%when%all%the%electrons%in%the%orbitals%are%paired%with%their%friend%of%opposite% spin% Paramagnetic-%at%least%one%electron%in%an%orbital%is%lonely%L% Apply%quantum%numbers%to%electron%configurations% Electron%configurations%are%written%as%nlnumber%of%electrons%...