-
1. :
) 0,02 HCl,
) 0,2 KOH.
| : c HCl = 0,02 c KOH = 0,2 |
) HCl = H+ + Cl-
= -lg c  ;
|
| pH ? |
HCl , α = 1,
+, l,
n 
= 1, 
= c 
= 0,02 / = 2 10-2 /.
= -lg210-2 = -lg2 + (-lg10-2)= 0,3 + 2 = 1,7.
) KOH = + + -;
= 14 ; = -lg c 
,
c 
= c 
α n 
,
, α = 1,
n -, , n 
= 1, c = c KOH = 210-1 /,
= lg(210-1) = lg2 + (lg10-1) = 0,3 + 1 = 0,7.
= 14 0,7 = 13,3.
: 0,02 HCl 1,7;
0,2 13,3.
0,05 (HOCl).
:
c  = 0,05
|
HOCl <=> H+ + OCl-
HOCl .
= lg[H+]; [H+] = c Olα n  ,
|
| pH ? |
n 
+ HOCl, n 
= 1.
;
HOCl HOCl:
= 5,010-8 (),
c = 510-2 10-3 1 = 5,0 10-5 /,
= lg5,010-5 = (-lg 5) + (-lg10-5) = 0,7 + 5 = 4,3.
: 0,05 HOCl 4,3.
3. MgF2, 25 º 1,17·10-3 /.
:
c  = 1,1710-3 /
| |
 ?
|
MgF2() <=> Mg2+ () + 2F-(),
= [Mg2+ ][F-]2,
[Mg2+ ] = c 
α n 
, [F-] = c 
α n 
.
MgF2 , α = 1;
n 
= 1, n 
= 2 ( )
[Mg2+ ] = 1,1710-311 = 1,1710-3 /;
[F-] = 1,1710-312 = 2,3410-3 /.
= 1,1710-3(2,34 10-3)2 = 6,4110-9.
: 
= 6,4110-9.
8.
B
1. - :
) (III),
)
.
| : ) (III) ) | ) Cr2(SO4)3 : Cr2(SO4)3 → 2Cr3+ + 3SO42- |
| - |
, , .
Cr2 (SO4)3
Cr (OH)3 + H2SO4
. .
2. - :
Cr 3+ + H+ OH - <=> + pH < 7, .
3. - . - , . , , :
|
|
|
Cr2(SO4)3 + 2H2O <=> 2CrOHSO4 + H2SO4.
) , ), - Na2S.
Na2S :
Na2S → 2Na+ + S2-.
Na2 S
NaOH + H2 S
. .
