Answers to lab activity 45 PDF

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Answer st oExer ci sesandPr obl ems f or

STRY CHEMI AGui de dI nqui r y Fi f t hEdi t i o n,2 0 1 1

Ri c ha r dS.Mo o g Fr ank l i n& Mar s ha l lCo l l e g e

J o hnJ . Fa r r e l l Fr ank l i n& Mar s ha l lCo l l e g e

La t e s tUpd at e :J u ne1 ,201 1

JohnWi l ey&Sons,I nc.

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Answer st oExer ci sesandPr obl ems Theseanswer smaybegi vent ost udent s. ChemAct i vi t y1 –=1 1 . A=31 ,n o . ofe 5.Z=8 ,A=18.39K+.Z=2 8,no . ofe–=2 6. – 2 4 – 2 3 2 . 1 . 67 4 1 0 g .1 . 9 93 1 0 g . – 1 7 3 . 8 . 67 1 0 g . 4 . 1 2. 0 0g . – 2 3g 5 . 7 . 30 5 1 0 . 6 . a )s umofp r o t on sa ndn e ut r on si nt henu c l e us .b)n umb e ro fp r o t o nsi nt h enu c l e us . 1 8 7 . Fa l s e . Oh a s8p r o t onsa n d10ne u t r ons . 8 . 1 2,1 2,1 2.10, 11,1 2.17, 17,1 8.18, 17,1 8.23, 26,3 0.7,7 ,8 .10,8 ,8 .10,1 3, 14. 5 9 2 + – 7 – 9 . Co .Z=7,A=14,n o .ofe =7. Li.Z=3 0,A=58 ,no .o fe =2 8.Z=9 ,A= – 1 9,n o .o fe =10 . 1 0. Al li s ot ope so fa ne l e me ntha v et hes a men umb e rofpr ot onsi nt henuc l e us .Onei s o t o peof a ne l e me nti sd i ffe r e nt i a t e df r o ma not h e ri s ot opeo ft hes a mee l e me n tb yt henu mb e ro f n e ut r onsi nt h enu c l e us . Pr o bl e ms 1 . Us i n gc a r b on1 3a ndc a r b on12 ,a ppr o xma s sofn e ut r on= 13 . 003 4–12= 1 . 0 034a mu . 1 4 a p pr o xma s sof C=13 . 003 4+1. 00 34=14 . 006 8a mu . – 1 4 1 4 2 . a )Us i n g Ca n d C ,ma s sofe l e c t r oni sa ppr o x i ma t e l y13 . 003 9a mu – 1 3. 00 34a mu= 0 . 00 05a mu 1 b )Us i n g H, ma s sofpr ot oni sa pp r o x i ma t e l y1 . 0 078a mu–0 . 00 05a mu=1 . 0 073a mu 1

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c )Us i n g H a nd H,ma s so fne u t r oni sa ppr o x i ma t e l y2. 0 140a mu–1. 0 078a mu = 1 . 00 62a mu ( No t et ha ts l i gh t l ydi ffe r e ntv a l ue sf ort hema s s e sofp r o t o nsa ndn e ut r o nswi l lbeo bt a i n e d i fd i ffe r e n te l e me nt s / i s o t o pe sa r eu s e dt oc a l c u l a t et he s ema s s e s . ) 3 . Thec a l c u l a t e dma s sof12Cb a s e dont h ema s s e soft hec ons t i t u e ntpa r t i c l e si s1 2. 09 9a mu; 1 2

a n dt hea c t u a lma s so f Ci se x a c t l y1 2a mu . ChemAct i vi t y2 1 . a ) 1. 0 08g .b ) 39. 1 0g . 2 . a ) 45 . 98g . b) 57. 2 7g . 3 7 4 . Clh a st womo r en e ut r on si ni t snuc l e us . 5 . a v e r a g ema s so fama r bl e= =  5. 0 0g+  7. 0 0g= 0 . 2 500 5. 00g+0. 75 00 7 . 0 0g= 6 . 50g( t hi si se q n( 2 ) ) 6 . 10. 4 4a mu 7 . 35Cl ,7 5. 7 6%.37Cl ,2 4. 2 4%. 8 . a ) 4. 0 03g b) 39 . 10g

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1mol eHeat oms 23 oms 4. . 022x10 Heat 9 . a ) 1Hea t o m 6 0 03gHe / mol eHea t oms – 2 4 = 6. 6 47 10 go fHe . 1mol eKat oms 23 Kat oms 39. . 022x10 0 98gK/ mol eKa t oms= b )1Ka t om  6 – 2 3 6 . 49 3 1 0 g .o fK 1 0. 6 0. 0 6g 2 4a 1 1. 3 . 6 13 1 0 t oms . 2 4 1 2. 2 . 6 19 1 0 a t oms . 1 9a 2 5a 1 3. a )3. 0 29 1 025a t oms .b)1 . 02 2 10 t oms .c )1 . 87 8 10 t oms .d )9 . 782 1 027 a t oms . 1 4. Ph os phor u s 1 5. 8 9. 5gI Pr o bl e ms 1 . ( 0 . 90 5) ( 19. 9 924a mu )+( 0 . 095 ) ( xa mu )=20 . 179a mu .Sol v ef orx :x=22. 0a mu .Thu s , mos tl i k e l y22Ne . 2 . a )Fa l s e .6. 9 41gpe rmo l eo fLia t o ms .b)Fa l s e .NoH a t o mswe i g hs1. 0 08a mu;t hi si s a na v e r a g ea t omi cma s s . c )Tr ue .Naa t omsa r emor ema s s i v e , s of e we ra t omsn e e de df o r s a met ot a lma s s . D)Fa l s e .Thi swoul di mp l yt ha ta na t om h a sama s so f0. 0 45a muwhi c hi s n otp o s s i bl ea si ti sl e s st ha nt hema s so fap r o t o n. 3 . 1 7:pr o t o nsi nn uc l e usa nde l e c t r o nsi nt hen e ut r a la t om.35 . 45 3:a v ga muofaCla t o ma nd gr a mso fon emo l eo fCla t oms . 4 . Re 187 ChemAct i vi t y3 1 . 5 . 47 1 0–18J . 2 . a )I Ea= – ( 2) ( – 1) / d / d1 b)I Eb = –( 1) ( – 1) / 2d1 = 1/ 2d Ea > I Eb 1 =2 1 I 3 . Thei o ni z a t i one n e r gyo fc a s e( a )i sl a r g e r , 1. 20k / d1, t ha nt ha tofc a s e( b) ,1 . 1 7k / d . 1 Pr o bl e ms 1 . l a r g ea ndn e g a t i v e ( – 1 ) ( – 1 ) k ( 2 ) ( – 1 ) k ( 2 ) ( – 1 ) k   400 pm pm 700 pm 2 . V= 300 ChemAct i vi t y4 1 . No .Thei o ni z a t i one ne r gyofHewou l dbea b out4 ( t wi c et hec ha r g ea ndh a l ft hed i s t a nc e ) t h ei o ni z a t i one n e r gyo fHi ft h i swe r et h ec a s e . 2 . Op e ne n de d.Al lt hr e ee l e c t r o nsa taf a r t he rdi s t a n c e( t h a ni nH)f r omt henuc l e us . Pr o bl e m

( 2 ) ( 1 ) k ( 1 ) ( 1 ) k ( 2 ) ( 1 ) k   d d 2 d 1 . a ) V=

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b ) TheI E ofHei ss l i g ht l yl e s st ha nt wi c et heI E ofH be c a u s et hee l e c t r on e l e c t r o n r e pul s i o nma k e st hep ot e n t i a le ne r gymo r ep os i t i v e .No t et ha tt h efir s tt wot e r msi n1 a )a r e n e g a t i v ea ndt het hi r dt e r mi sp os i t i v e . ChemAct i vi t y5 1 . a )4 .b )6 .c )5 . d )8 . 2 . a )+4. b )+6 . c )+5 . d )+8. 3 . Th eI EofBrs ho ul dbel e s st h a nt h eI EofCl .Th e r ei sa bo uta0 . 4MJ / mo l edi ffe r e n c e b e t we e nt heI Eso fFa ndCl .Pr e di c t i o n:Br ,0 . 8MJ / mo l e . 4 . Th eI Eo fLi +s ho ul db el a r g e rt ha nt h eI Eo fHebe c a u s eb o t ha t omsh a v e2e l e c t r onsi nt he s t + 1s he l la n dLih a sac o r ec ha r g eo f+3wh e r e a sHeo nl yha sac or ec ha r g eo f+2 . – 5 . Th eI EofF s h oul dbel e s st h a nt h eI EofNebe c a us ebo t ha t omsh a v ee i g hte l e c t r on si nt he n d – 2 s h e l la n dF h a sac or ec ha r g eo f+7whe r e a sNeh a sac o r ec ha r g eo f+8 . 6 . I EofKr>I Eo fBrbe c a u s et he ya r ei nt hes a mev a l e nc es he l la ndKrha st hehi gh e rc or e c ha r g e( +8v s .+7) .I Eo fRbi st hel o we s tb e c a us ec or ec ha r g ei s+1a n di t sv a l e nc es he l l( n =5)i sl a r g e rt ha nt hev a l e nc es he l l( n=4)o fKra n dBr . 7 . On eoft hei n ne rs he l le l e c t r on si sha r de rt or e mo v eb e c a u s ei ti sc l o s e rt ot henu c l e us . Pr o bl e ms 1 .a )Tr ue .Bri sagr ou pVI Ie l e me nt .Then umb e rofv a l e nc ee l e c t r onsi ss e v e n. b) Tr ue .Th efir s ti o ni z a t i one ne r gyi nc r e a s e sa sonemo v e sf r om l e f tt or i gh ta c r os sa p e r i oda nda son emo v e su pagr oup. 2 . I ft hef our t he l e c t r oni nBewe r ea dde dt oat hi r ds he l l ,i twoul dbee a s i e rt or e mo v ea ndt he I Ewo ul db el e s st ha nt heI EofLi . ChemAct i vi t y6 –) 1 . Ar :p r e di c tr=150pm ( l a r g e rt h a nK+buts ma l l e rt h a nCl .N:pr e di c tr=71pm ( l a r g e r –,b t h a nO b uts ma l l e rt ha nC) . F–:pr e d i c tr=9 0pm ( c on s i de r a bl ys ma l l e rt ha nCl ut n dp p r o bab l yl a r g e rt ha no t he r2 e r i odn e ut r a la t oms .Ne :p r e di c tr=5 0p m( s ma l l e rt ha nO) . 2 . a )Fa l s e .Bo t hh a v eac or ec ha r g eof+2a ndt hev a l e nc ee l e c t r on sofBaa r emu c hf a r t he r a wa y .b )Fa l s e .Bot hh a v e10e l e c t r onsa nds o di u m ha smo r epr o t ons .c )Tr u e .Bot hha v e 1 8e l e c t r o nsa n dc hl o r i neh a sf e we rp r o t on s .d )Tr ue .Awh ol es h e l lh a sbe e na dd e df o rAr . 2 + 2 + e )Fa l s e .Ara ndCa a r ei s o e l e c t r on i ca ndCa h a smo r ep r o t ons . + 2 + 3 . a )N b)K c )Cl d )H e )Mg 2 + 4 . Fe 5 . a )Pb b)Na c )Ba2+ d )H– e )Rb f ) P3– Pr o bl e ms 1 . Na .Thes e c on de l e c t r o nr e mo v e dwou l db eac or ee l e c t r on. 2 + 2 . Mg i si s oe l e c t r o ni cwi t hNe .Mg2+i ss ma l l e rt ha nNeb e c a us ei th a st womo r ep r o t o ns 2 – t h a nNe .S i si s oe l e c t r o ni cwi t hAr . S2–i sl a r g e rt ha nArbe c a u s eArh a st womo r e 2 – p r o t o nst ha nS.Ari sl a r g e rt ha nNe .The r e f or e ,S i sl a r g e rt ha nMg2+.

5 Che mAc t i vi t y7 1 . Fa l s e .Thes ho r t e rt hewa v e l e n g t h,t hegr e a t e rt hef r e q u e nc y . 2 . – 1) Re g i ono fSpe c t r u m Ene r gy( J ) Wa v e l e n gt h( m) Fr e q u e nc y( s 1 4 i nf r a r e d 9 . 94 1 0–20 2 . 00 1 0–6 1 . 50 1 0 1 4 v i s i bl e 3 . 97 1 0–19 0 . 50 0 1 0–6 6 . 00 1 0 1 5 u l t r a v i ol e t 1. 5 0 10 9 . 94 1 0–19 2 . 00 1 0–7 1 7 Xr a y 1 . 99 1 0–16 1 . 00 1 0–9 3 . 00 1 0 3 . Ab l u epho t oni smo r ee n e r g e t i c .Thee ne r gyi si n v e r s e l ypr opo r t i o na lt ot hewa v e l e n gt h. Pr o bl e m – 1 9 1 . No .Thee ne r gyr e q ui r e dt oi on i z eas odi um a t om i s8. 3 0 10 J . A pho t onwi t ha – 1 9 wa v e l e n gt ho f5 00n mh a son l y3 . 96 10 J .

ChemAct i vi t y8 1 . 140. 3MJ / mo l e 2 . a )

3 .

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ChemAct i vi t y9 1 . a )Two .b)Lo we re ne r gype a k( 1s )i s2xt h ei nt e ns i t yoft heh i g he re n e r gype a k( 2s ) .c ) Th en uc l e a rc ha r g ef orH,He ,a ndLii s1,2,a nd3,r e s pe c t i v e l y .The r e f o r e ,t hee l e c t r on si n t h efir s ts h e l lwi l lb ehe l dmo s tt i gh t l yb yLia ndl e a s tt i g ht l yb yH.d )H a ndLiha v et h e s a mec o r ec h a r g e ;t hee l e c t r oni sf a r t he ra wa yi nLi .The r e f o r e ,Liwi l lh ol di t sv a l e n c e e l e c t r onl e s st i g ht l yt ha nH. 2 . Be .Twop e a ks .Bot hp e a ksh a v et hes a mei nt e ns i t y . C.Th r e ep e a ks .Al lt hr e epe a ks h a v et hes a mei nt e n s i t y .

4 . Mg . Twoe l e c t r onsi nt he1s . Twoe l e c t r o nsi nt he2s . Si xe l e c t r o nsi nt he2p . Two e l e c t r onsi nt he3 s . Pr o bl e ms 1 . a )Fa l s e .Bo t hh a v e10e l e c t r o ns .Then umb e rofp e a ksa ndt h er e l a t i v ei nt e n s i t i e swi l lbe 2 + t h es a me ,butt h eI EsofMg wi l lbegr e a t e rt ha nt hee q ui v a l e ntI EsofNe .b)Tr ue .Bo t h h a v e17e l e c t r o nsa n d17pr o t ons . 2 .2 73MJ / mol e .Thee n e r gyr e q u i r e dt or e mo v ea ne l e c t r onf r o mt h e1sofClmus tbemu c h h i gh e rt ha nt hee ne r gyr e q ui r e dt or e mo v ea ne l e c t r o nf r om t he1sofFbe c a u s eClha s17 p r o t o nsi ni t sn uc l e usa ndFonl yha s9pr ot onsi ni t snuc l e u s .

7 ChemAct i vi t y10 1 . Naha s11p r o t o nsi ni t sn uc l e usa ndNeo nl yha s1 0p r o t on s .Th e r e f or e ,t he1se l e c t r o ns wi l lb eh e l dmo r et i gh t l yi nNa . 2 .I twoul dr e q ui r emor et ha n0. 50MJ / mo l ebe c a us eMg+1a n dNaa r ei s oe l e c t r o ni ca ndMg h a sa na ddi t i ona le l e c t r oni ni t sn uc l e us . ChemAct i vi t y11 1 . Kr 2 . C...