Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.chem.msu.ru/rus/olimpiad/olimp2003/anal_r_.pdf Дата изменения: Thu May 29 14:32:24 2003 Дата индексирования: Sat Dec 22 12:20:18 2007 Кодировка:

I.
I ( ..)
1. (), (). , . - ). (1 ) 2. Q (3). , , , Q, .. 1 2. Q, , , : d[P]/dt = k1[H2O2][H2Q] + k2[H2O2][H2Q][Cu2+] (1 ) 3. (1 2). (-d[H2O2]/dt)1 = k1[H2O2][H2Q] + k2[H2O2][H2Q][Cu2+] -, , , (2- ). , : (-d[H2O2]/dt)1+2 = 2k1[H2O2][H2Q] + 2k2[H2O2][H2Q][Cu2+](5 ) 4. ( , ). (..) (/), , . , , C
Cu

= 0

(1). , -. , : (56-22)/(4-1) = 11.33 ../·-1, y ( ): 22 - 1в11.3 =10.7 .. , , : 40-10.7 = 29.3 .. , : 29.3/11.3 = 2.6 /. (5 )

2 ( .)
1. . tR, k . 1: -4 -5 -6
10 12 14

n

C

tR, 32.5 45 70

k 0.625 1.25 2.5

logk -0.204 0.097 0.3979





,°

4 5 6

----68,8


-7 - CyH
z

16 2+2

7 -----

120 418 91 200

5 20.9 3.55 9.0

0.6990 1.2988 0.550 0,954

98,5 ? --124

-p

2p+2

k , , kn = 0.625в2
n-4

, logkn = log0.625 + (n ­ 4) log2 = 0.301n ­ 1.408 .

, logk = 1.2988, : 1,2988 = 0.301 - 1.408, = 9.06, .. ­ -. : , ( ) logk (nC) : logk = a + bnC, a b ­ , , , , , : 0.3979 = +6b 0.699 = a + 7b; b = 0.301; a = ­1.408. : 1,2988 = -1.408 +0.301x; x = 9; ­ -C9H18. . k = (tR­t0)/t0=3.55 logk, IB : IB = 100(log3.55­log2.5)/(log5­log2.5) + 600 = 650.6 . 2 , ­ . ( 3 A B) 2. , : logk = A2 + B2T


.

( .): : 0,3979 = 2 +68,8 : 0,699 = 2 + 98,5
2

2

2 = 0,0101; 2 = ­0,2970. : 1,2988 = ­0,2970 +0,0101в


();



() = 158.

:

logk = 2 + 2· = ­0.297 + 0.0101 · 124 = 0.955 , k = 9.0, . k (, ) ( , ) . (3 )


3. -: = A + B/V + CV. . V, ­ , dH/dV = ­B/V2 + C = 0. .. V


= (B/C)1/2.

- , . V F : F = VS, S ­ , S = R2 = d2/4 = 1.257 2; V1 = F1/S 15 /; V2 = F2/S 40 /; 1 2 V1 V2: H1 = 500/12250 = 0.0408 ; H2 = 500/11000 = 0.045 . : 0.0408 = /15 + 15 0.045 = /40 + 40; = 0.42; = 8.610-4. V


= 22 /; F = L/H




= 17.5 /;



= 0.42/22 + 8.610-422 = 0.038 ;

N

= 500/0.038 = 13155 .

( 3 )

3 ( ..)
1. : : : -:

Ca:C:O:H = 27,40/40 : 16,44/12 : 54,79/16 : 1,37/1 = 1:2:5:2 CaC2O4·H2O ( ) CaC2O4·2H2O ( ) Ca:H:P:O = 0,58:2,91:0,58:3,49 = 1:5:1:6
(0.4 )

(0.4 )

Ca:C:O:H = 24,39/40 : 14,63/12 : 58,54/16 : 2,44/1 = 1:2:6:4
(0.4 )

(0.4 )

(0.4 ) (0.4 )

CaHPO4·2H2O ( ) C:H:N:O = 2,98:2,38:2,38:1,79 = 5:4:4:3 C5H4N4O
(0.8 )

3 (0.8 )

: a10(PO4)6(OH)2 2.

, 3:

[H2X­] = (1 + 2)/2 = 3,95 [HX2­] = (2 + 3)/2 = 5,57 [H2X­] = [HX2­] = 2 = 4,76
(0.5 )
1

= 3,14 (1= 1,24·10­4)
(0.5 )

(0.5

)

,

2

= 4,76 (2= 1,14·10­5)

, 3= 6,38 (3 = 4,17·10­7)

.


3. a) < pKa1 ­ 1 = 2,14 ( < pKa1 ­ 2 = 1,14) b) > pKa3 + 1 = 7,38 ( > pKa3 + 2 = 8,38) c) = pKa3 = 6,38, .. 3= [X3-][H+]/[HX2-] = 1·[H+] 4.
(0.5 ) (0.5 ) (0.5 )



( , . ., .. , - , 1984, .172 .. , 1986, .41):

H 3X =

[H 3 X] [H + = C H3X [H + ]3 + K a1[ H + ] 2 + K a1
-3,14

]3 K a 2 [H + ] + K a1K a 2 K a 3
- 4,76

= = 5,6 10 -7

(10 -6,8 ) 3 (10
-6,8 3

) + 10

H 2X

(10

-6,8 2

) + 10

-3,14

10

10

-6,8

+ 10
+

-3,14

10

- 4,76

10

-6,39

-

=

K a1 [H + [H 2 X - ] = C H 3X [H + ]3 + K a1[H + ] 2 + K a1K a

]2
2

[H ] + K a1K a 2 K a 3

= 2,5 10 -3



HX

2-

=

K a1K a 2 [H + ] [HX 2- ] = = 0,28 C H 3X [H + ]3 + K a1[H + ] 2 + K a1K a 2 [H + ] + K a1K a 2 K a 3



X

3-

K a1K a 2 K a 3 [A 3- ] = = = 0,72 +3 +2 C H3X [H ] + K a1[H ] + K a1K a 2 [H + ] + K a1K a 2 K a 3

(3) : (2­) : (2­) : (3­) = 5,6·10­7 : 2,5·10­3 : 0,28 : 0,72 = 1 : 4,5·103 : 5·105 : 1,28·106 (2 ) 5. , = 6,8 - -. ( ): 0 = [HX2­] + [X3­] =


+

2­

.4 - -, (3­) / ( ) = 1,28·106/5·105 = 2,56 , : 0 = [HX2­] + [X3­] = [HX2­] + 2,56[HX2­] = 3,56[HX2­]

4, 3:
K a3 = [H + ][X 3- ] [HX 2- ] ; [X 3- ] [HX 2- ] = K a 3 10 -6,39 = = 2,56 [H + ] 10 -6,8

: [K+] + [H+] = [OH­] + 2[HX2­] + 3[X3­]


[K+] +10

­6,8

= 10

­7,2

+ 2[HX2­] +7,68[HX2­]
=[H +

[K+] = 9,68[HX2­] ­ 9,54·10­8 ; ]/3 (1,5 ) 9,54·10­8 [K+]/C0:
[K + ] 9,68[HX 2- ] = = 2,72 = 3 C0 3,56[HX 2- ]


/(C



+



).

9.7 (0.5 ). 6.



/



= 9.7

, ,

-, , . -, (1 ). 7. : aC2O4·22
()


3­

+X

CaX­ + C2O

4

2­

+ 22

[CaX - ][C 2 O 4 2- ] = = aC2O 4 K = 1,8 10 -9 10 4,68 = 8,61 10 -5 3- [X ]

, - 3­, 0,72 (. .4). S / , S / - ( 0,72·0,012 ­ S = 8,64·10­3 ­ S). S / . :
= [CaX - ][C 2 O 4 2- ] S2 = = 8,61 10 -5 (1.5 ) 3- -3 [X ] 8,64 10 - S

S = 8,21·10­4 / (0.25 ) = 0,135 / (0.25 ). . -, . 8. 1=5,75 2=10,3 =6,8 HY­, , , H2Y 11:1. :
K a1 = [H + ][HY - ] [H 2 Y] ; [HY - ] K a1 10 -5,75 = = 11 (1 ) [H 2 Y] [H + ] 10 -6,8
1

= 1,4

2

= 4,3, =6,8

-,