ÓɱíµÃ£ºpH=1.0, lg?Y(H)?17.13,?×îµÍpHΪ1.0 ÓÉ[Fe3+][OH]3=Ksp,
1.0?10?36[OH]???4.79?10?12mol/L 3??2[Fe]1.0?1033KsppOH=11.3 £¬pH=2.7£¬×î¸ßpH=2.7
(2) pH=10ʱ£¬lg?Y(H) = 0.45; lg? Fe(OH) = 0.6, lg¦Â1~ ¦Â3·Ö±ðΪ5.2¡¢9.2¡¢11.9
?Fe(F)?1??1[F]??2[F]2??3[F]3?1?105.2?0.10?109.2?(0.10)2?1011.9?(0.10)3 ?108.91?Fe??Fe(F)??Fe(OH)?1?108.91?100.6?1?108.91,?Y??Y(H),
?ÔòlgKFeY
?lgKFeY?lg?Fe?lg?Y?25.1?8.91?0.45?15.74
2. ÔÚEDTAÅäλµÎ¶¨ÖУ¬ÈôCd2+Àë×ÓµÄŨ¶ÈΪ0.020mol/L, ÈÜÒºµÄpH=5£¬ÓÎÀë°±µÄŨ¶ÈΪ0.10 mol/L£¬ÒÔ¶þ¼×·Ó³ÈΪָʾ¼Á£¬¼ÆËãµÎ¶¨ÖÕµãÎó²î¡£ ½â£º²é±íµÃ£ºlgKCdY=16.46£¬lg¦Â1~ ¦Â4·Ö±ðΪ2.6¡¢4.65¡¢6.04¡¢6.92£¬ pH=5ʱ£¬lg?Y(H) = 6.45£¬lg?Cd(OH) = 0 (1)
?Cd(NH)?1??1[NH3]??2[NH3]2??3[NH3]3??4[NH3]43?1?102.60?0.10?104.65?(0.10)2?106.04?(0.10)3?106.92?(0.10)4 ?2414.74?103.38?? ?Cd??C(d3N)H(Cd)OH.38?1?130.38?100?1?1 30 ?Y??Y(H)
??lgKCdY?lg?Cd?lg?Y?16.46?3.38?6.45?6.63 lgKCdYcCd(sp) =0.010 mol/L
[Cd2?']?cCd(sp)'KCdY?0.010-4.32?10 106.63pCd'??lg[Cd2?']??lg10?4.32?4.32
17
pHΪ5ʱ£¬Ö¸Ê¾¼Á±äÉ«µã:
pCdt?lgKCdIn?lg?In(H)?4.5 ?pCd'?pCdt?pCd'?4.5?4.32?0.18
TE(%)?10?pM?10??pMcM(SP)K'MY''?100%?100.18?10?0.180.01?10
6.63?100%?0.002%
µÚÁùÕ Ñõ»¯»¹ÔµÎ¶¨·¨Ï°Ìâ½â´ð
2¡¢½â:
¡ß [Y¡¯]=0.10mol/L
[Y'][Y']0.10?[Y]??13.51?10?14.51 ?Y(H)?[Y]?Y(H)10 ?FeY??1?KFeY?[Y]?1?1025.1?10?14.51?1?1010.59 ?FeY2??1?KFeY2?[Y]?1?1014.32?10?14.51?1?10?0.19
?FeY2??'? ?Fe3?/Fe2????0.059lg?FeY?
1?10?0.19?' ?Fe3?/Fe2??0.771?0.059lg?0.135V10.591?10
?'?' ¡ß ?Fe3?/Fe2??0.135V??I2/2I??0.534V
·´Ó¦Ïò×ó½øÐС£
3. ÓÃKMnO4±ê×¼ÈÜÒºµÎ¶¨Fe2+µÄ·´Ó¦Îª£º
MnO42- + 5Fe2+ + 8H+ == Mn2++ 5Fe3+ +4H2O
ÊÔ¼ÆË㣺¢Ù¸Ã·´Ó¦µÄƽºâ³£Êý£»¢ÚΪʹ·´Ó¦ÍêÈ«¶¨Á¿½øÐУ¨[Fe2+]¡Ü10-3[Fe3+]£©,ËùÐèµÄ×îµÍ[H+]ÊǶàÉÙ£¿£¨ÒÑÖª £©
?'?'?Fe?0.771V,??1.51V3?2??½â£º /FeMnO4/Mn2?
n???'5?(1.51?0.771)'lgK???62.63
0.0590.059
18
4
[Fe3?]??3 ?Fe3?/Fe2????0.059lg?0.771?0.059lg10?0.948V2?[Fe] ?][H?]80.059[MnO40.059??3?8????lg?1.51?lg(10?[H])?0.948?2? 2?MnO4/Mn5[Mn]5
[H+]=2.6¡Á10-6 mol / L
4. ÔÚ25¡æ£¬1mol/L HClÈÜÒºÖУ¬ÓÃFe3+±ê×¼ÈÜÒºµÎ¶¨Sn2+Òº£¬¼ÆËã¢ÙµÎ¶¨·´Ó¦µÄƽºâ³£Êý²¢ÅжϷ´Ó¦ÊÇ·ñÍêÈ«£»¢Ú»¯Ñ§¼ÆÁ¿µãµÄµç¼«µçλ£»¢ÛµÎ¶¨Í»Ô¾µçλ·¶Î§£¬ÇëÎÊ¿ÉÑ¡ÓÃÄÄÖÖÑõ»¯»¹Ôָʾ¼ÁָʾÖյ㣿£¨ÒÑÖª £©
?'?'½â£º¢Ù ?Fe3?/Fe2??0.70V,?Sn4?/Sn2??0.14Vnn(???2)1?2(0.70?0.14)lgK?121??18.98 0.0590.059K'?1018.98?9.5?1018'0?0?K¡ä=1062.63
·´Ó¦¶¨Á¿½øÐУ¬Ôò
[Fe3+]=103[Fe2+], [Mn2+]=103[MnO42-], ·´Ó¦Æ½ºâʱ ??'?Fe??MnO3??/Fe2?/Mn2?ÒòΪn1:n2=1:2, ÇÒlgK¡¯>9,ËùÒÔ·´Ó¦ÄܽøÐС£
¢Ú µÎ¶¨·´Ó¦ 2Fe3??Sn2?2Fe2??Sn4?
3?Fe2??0?Fe3?/Fe2??0.70V°ëµç³Ø·´Ó¦£º Fe?eSn2??0?Sn4?/Sn2??0.14V Sn4??2en??n2?21?0.70?2?0.14»¯Ñ§¼ÆÁ¿µãµçλ£º?sp?11??0.33(V)
n1?n21?2¢ÛµçλͻԾ·¶Î§£º??0.1%??2?0?0?0?0?0.059?30.059?3?0.14??0.23(V) n22 ??0.1%??1?ÑǼ×À¶Ö¸Ê¾¼ÁµÄ?0?0.059?30.059?3?0.70??0.52(V) n11?0.36(V)£¬Î»Óڵ樵çλͻԾ·¶Î§£¨0.23V~0.52V£©ÄÚ£¬Òò
¶øÑ¡ÑǼ×À¶×÷ָʾ¼ÁΪÒË¡£
19
5. ÓÃK2Cr2O7±ê¶¨Na2S2O3ÈÜҺʱ£¬³ÆÈ¡0.5012g»ù×¼K2Cr2O7£¬ÓÃË®ÈܽⲢϡÊÍÖÁ100.0ml£¬ÎüÈ¡20.00ml£¬¼ÓÈëH2SO4¼°KIÈÜÒº£¬Óôý±ê¶¨µÄNa2S2O3ÈÜÒºµÎ¶¨ÖÁÖÕµãʱ£¬ÓÃÈ¥20.05ml£¬ÇóNa2S2O3
ÈÜÒºµÄŨ¶È¡£(MK2Cr2O7294.19)
2-½â£º·´Ó¦Îª£º Cr2O7+ 6I-+ 14H+
2-I2 + 2S2O3
2-1molCr2O72Cr3?+ 3I2 + 7H2O
2-2I- +S4O6
3molI2?20.00100.0?32- 6molS2O3 £¬¹Ê nSO2-?6nCrO2-
23276?cNa2S2O3mK2Cr2O7MK2Cr2O76???VNa2S2O3?100.501220.00?294.19100.0?0.1020mol/L 20.05?10?3
6£®½ñÓе¨·¯ÊÔÑù£¨º¬CuSO4¡¤5H2O£©0.5580g£¬ÓõâÁ¿·¨²â¶¨£¬µÎ¶¨ÖÁÖÕµãʱÏûºÄNa2S2O3±ê×¼ÈÜÒº£¨0.1020mol/L£©20.58ml¡£ÇóÊÔÑùÖÐCuSO4¡¤5H2OµÄÖÊÁ¿·ÖÊý¡££¨MCuSO4?5H2O249.69£© ½â£º
2Cu2??4I?I2 +2S2O32-2CuI??I22I- +S4O62-Cr2O7 2- + 6I-+ 14 H+I2 +2S2O32-2Cr3+ + 3I2 + 7H2O
2molNa2S2O3
2I- +S4O62-2molCuSO4¡¤5H2O2molCu2+1molI2¼ÆËãCuSO4¡¤5H2Oº¬Á¿£ºnCu2??nS2O32?
CuSO4?5H2O%?
cSO2?VSO2??MCuSO4?5H2O23231000ms?0.1020?20.58?249.69?93.9%
1000?0.55808. ³ÆÈ¡±½·ÓÊÔÑù0.1528g£¬ÖÃ100 mlÁ¿Æ¿ÖУ¬¼ÓË®ÊÊÁ¿Ê¹ÈܽⲢϡÊÍÖÁ¿Ì¶È£¬Ò¡ÔÈ£»ÒÆÈ¡20.00mlÓÚµâÆ¿ÖУ¬¼ÓäåÒº£¨KBrO3+KBr£©25.00ml
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