Chemistry1A Fall2017

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Exam1

Youwillhave120minutestocompletethisexam.Pleasefillinthebubblethatcorrespondstothecorrectanswerontheanswersheet.Onlyyouranswersheetwillbegraded.

Eachquestionhasonly1correctanswerunlessotherwisespecifiedinthequestion.Youareallowedtousetheprovidedequationsheetandperiodictabletohelpyouanswerthequestions.

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1. Howmanygramsofwaterareformedwhena10gsampleofacetylene(C2H2)burnsinexcessoxygen(O2)?

A)5g B)7g C)10g D)18g E)20g

2. Whenthereactionforthedecompositionoftwomolesofsilvercarbonateisbalanced,whatisthestoichiometriccoefficientforcarbondioxide(CO2)?

2Ag2CO3––>__Ag+__CO2+__O2

A)0 B)1 C)1.5 D)2 E)3

3. Whichofthefollowingstatementsistrueforchemicalreactions?

A) Thenumberofmolesofproductsisthesumofthemolesofreactants.

B) Totalmassisconservedbetweenproductsandreactants.C) Thenumberofmolesisconservedbetweenproductsandreactants.D) Thenumberofmoleculesisconstant.E) Noneofthese.

4. Whichistheformulaofacompoundwhosecombustionproductsgivethefollowingmassspectrum?

A)C2H2O B)C3HO2 C)C6H8O6 D)C6H12O4 E)C7H5O2

5. Whatisthefrequency(inHz)ofanelectromagneticwaveofwavelength5000nm?

A)5.00x1010Hz B)6.00x1013Hz C)7.00x1015HzD)8.00x1017Hz E)9.00x1023Hz

6. Whichmoleculeorionwillhavethelowestionizationenergy?

A)H(2p1) B)He(1s13p1) C)Li(1s24p1)D)Be(1s22s15p1) E)B(1s22s26p1)

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7. Foraparticleinaboxwiththeenergiescorrespondingtothefollowingwavefunctions:

Whichabsorptionniànfrequiresthehighestenergyphoton?(ChemQuiz5.2).

A)1à2 B)2à3 C)3à1

8. WhichofthefollowingobjectshasthelongestdeBrogliewavelengthwhenallaretravelingatthesamevelocity?

A)Bowlingball(2kg) B)Golfball(50g) C)Pingpongball(1g)D)Baseball(105g) E)Basketball(1500g)

9. Hydrogenhastwostableisotopes,1Hand2H,andcarbonhastwostableisotopes,

12Cand13C.Whichisotopicspeciesofmethane(CH4)willgiveapeakatmass18inamassspectrometer?

A)12C1H4 B)12C1H22H2C)13C1H2H3 D)12C1H2H3E)13C2H4

10. Lightof450nmwavelengthwillejectelectronsfromametalsample.Whichalsomustbetrue?

A) Lightof500nmwillalsoejectelectronsB) Lightof400nmwillalsoejectelectronsC) 450nmlightofgreaterintensitywillejectelectronswithgreater

velocityD) 600nmlightwillejectelectronsprovidedtheintensityisgreat

enough.E) Nonearetrue

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11. Aphotonofbluelightwithawavelengthof400nmsplitsintotwoidenticalphotons.Knowingthatenergyisconserved,whatisthewavelengthofeachofthesetwophotons?

A)200nm B)283nm C)400nm D)566nm E)800nm

12. Basedonthetrendsinthefigurebelow,whichatomhasthehighestionizationenergy?(ChemQuiz9.2)

A)Cl B)Ar C)K

13. Howmuchenergyisrequired(injoules)toionizethehydrogenatom?

A)3.3x10-15J B)2.2x10-18J C)6.6x10-10JD)2.1x10-17J E)4.3x10-20J

14. WhichtransitioninHe+correspondstothesameenergydifferenceasn=2ton=1inH?

A)2to1 B)3to1 C)4to1 D)4to2 E)4to3

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15. Whichcolordoesanorangesolutionappeartobewhenviewedthroughafilterwithabsorptionprofileshownhere?

A)Clear B)Green C)Blue D)Black E)Wecan’ttell

16. Whichatomhasthegreatestnumberofneutrons?

A)27Al B)28Si C)32S D)32P E)35Cl

17. Whichbestdescribestheatomicstructureofthe56Fe2+ion?A)56electrons,56neutrons,56protonsB)2electrons,56neutrons,56protonsC)24electrons,30neutrons,26protonsD)26electrons,30neutrons,26protonsE)26electrons,28neutrons,28protons

18. Whichofthefollowingisavalidsetofquantumnumbersforanelectronina3dorbital?

A)mℓ=0,ℓ=2,n=3 B)mℓ=3,ℓ=3,n=3 C)mℓ=1,ℓ=3,n=2D)mℓ=-1,ℓ=1,n=3 E)mℓ=3,ℓ=2,n=3

19. Whichneutralatomcouldhavetheelectronicconfiguration1s22s22p63s23p44s1?

A)K B)Cl C)Na D)Rb E)S

20. WhatisthechargeonaBoronionwith7electrons?

A)-2 B)-1 C)0 D)1 E)2

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21.Whichorbitallistedbelowhasthegreatestnumberofradialnodes?

A) 1s B) 2p C) 3s D) 4d E) 5f

22. Forwhichspeciesdoestheenergyleveln=1haveanenergyof-9R∞?

A) H B) He+ C) Li2+ D) Be3+ E) B4+

23.Whichionhasthegroundstateelectronicconfigurationof[Ar]3d5?

A) V3+ B) Mn2+ C) Cu+ D)Co2+ E) Tc2+

24.Whichcompoundhasthehighestpercentageofchlorinebymass?

A) HCl B) KCl C) MgCl2 D) BaCl2 E) AlCl3

25. Relativetoanelectron’senergylevelinanatom,whichconditionrepresentszeroenergy?

A) Theelectronandnucleusinfinitelyseparated.B) Thegroundstate.C) Thenucleus.D) Thereisnozeropointintheelectronicenergylevelscheme.E) Noneofthese.

26. Whichneutralatominitsgroundstateisparamagnetic?

A) He B) Ar C) Ca D) Mg E) C

27.Whichistheproperorderingofthefollowingelementsfromlowestionizationenergytohighest?

A) Ar,S,Si,Mg,NaB) Mg,S,Si,Na,ArC) S,Ar,Si,Na,MgD) Mg,Na,Ar,S,SiE) Na,Mg,Si,S,Ar

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28.Whichspecieshasthehighestionizationenergy?

A) Br– B) Kr C) Sr2+ D) Rb+ E) Se2-

29.Whichofthefollowinghasthelargestatomicradius?

A) Li B) C C) As D) Br E) K

30. Cadmiumhydroxidecontains76.77%cadmiumbymass.Whatistheempiricalformulaofcadmiumhydroxide?(Atomicmasses:Cd:112.41g/mol,H:1.01g/mol,O:16.00g/mol)

A) CdOH B) Cd(OH)2 C)Cd(OH)3 D)Cd(OH)4 E)Cd(OH)5

31. Howmuchenergyisreleased(inRydbergs)whenaHe+ionrelaxesfromits2pstatetoits1sstate?

A) 1 B) 2 C) 3 D) 4 E) 5

32. Theelectronconfigurationforoxygenisshownbelow.Whatarepossiblequantumnumbersforthelastelectronadded?

A) n=2,l=0,ml =0,ms=1/2

B) n=3,l=1,ml =0,ms=-1/2

C) n=2,l=0,ml=2,ms=1

D) n=2,l=1,ml=-1,ms=-1/2

E) n=1,l=0,ml=0,ms=1/2

Chemistry 1A Midterm Exam 1 February 12, 2013Professor Pines 5 pages total

Student Name: _____________________________________ Student ID#: ________________________

Potentially Useful Information

Violet Blue Green Yellow Orange Red

400 500 600 700 Wavelength (nm)

Light: c= , hEphoton = , c = 2.99792 x 108 m s-1 NA = 6.02214 x 1023 mol-1

Photoelectric Effect: 0hhhKEelectron == h = 6.62608 x 10-34 J s

Matter: mvp = , R = 3.28984 x 1015 Hz

Wave/Matter: ph

deBroglie = = hR = 2.17987 x 10-18 J

Particle 1D box: 2

22

8mLnhEn = ; n = 1, 2, 3...

H atom, 1-electron ion:

1312 kJ/mol

= RnZEn 2

2

; n = 1,2,3…

me = 9.10938 x 10-31 kg

Orbital Nodes: Total = n – 1, Angular = l, Radial = n – 1 – l

. H Na K Rb Cl Br I . Ionization Energy [IE] (kJ/mol) 1312 496 419 403 1251 1140 1008 . Electron Affinity [EA] (kJ/mol) 73 53 48 47 349 325 295 .

You may verify that the IE of atomic H corresponds to UV light with a photon wavelength of 91 nm.

Ekin= mv2 =12

p2

2m

R∞

kg ms2

J =