: c = 0,05 |
pH -? |
:
HOCl <=> H+ + OCl- (7.3)
HOCl - .
= - lg [H+]; [H+] = cOlαn ,
n - + HOCl, n = 1.
HOCl - HOCl:
=5,010-8, (.),
c = cOlαn = 510-210-31 = 5,010-5 /,
= - lg5,010-5 = 4,3.
: 0,05 HOCl 4,3.
3. MgF2, 250 1,17·10-3 /.
: c = 1,1710-3 / |
-? |
:
:
MgF2() <=> Mg2+ () + 2F-() (7.4)
= [Mg2+ ][F-]2,
[Mg2+ ] = c αn , [F-] = c αn .
MgF2 - , α = 1.
n = 1, n = 2 ( 7.4)
[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
1. , 25 3 0,1 HCl, 20 3 0,2 NaOH 50 3 .
: = 203 = 0,2 / = 253 = 0,1 / |
-? |
:
NaOH + HCl → NaCl + H2O (7.5)
:
= · = 0,2 ·20·10-3 = 4·10-3 = 0,004 ,
= · = 0,1·25·10-3 = 2,5·10-3 = 0,0025
10-3 .
(7.5) , NaOH, , HCl.
, :
0,004 > 0,0025 .
, , NaOH.
NaOH :
= 0,004 - 0,0025 = 0,0015 .
, ,
= + + = 25·10-3 + 20·10-3 + 50·10-3 = 95·10-3,
NaOH :
= = 0,016 /.
NaOH :
NaOH = Na+ + OH-,
= 0,016 /.
= - lg = - lg 0,016 = 1,80.
= 14 ,
= 14-1,80 = 12,20.
: = 12,20.
2. , , 100 0,01 200 0,02 .
: = 0,01M = 0,02M V = 100 c V = 200 c |
? |
:
:
aCl2+Na2CO3= CaCO3↓+ NaCl (7.6)
CaCO ,
> =510 (.)
100 c CaCl 200 c Na CO , 300 c . Ca2+ CO 2- :
= n ; = n
|
|
CaCl Na CO - , = 1.
CaCl Na CO :
CaCl = Ca +2Cl
Na CO = 2Na +CO
, n = 1 n = 1.
= 0,0111 = 3,310 /,
= 0,0211 = 1,310 /.
= 3,310 1,310 = 4,2910
4,2910-5 > 510-9 ( ), CaCO .
: CaCO .
3. 0,0IM HNO2, , , 0,02 / KNO2.
: = 0,01 M = 0,02 M |
-? |
:
= - lg
HNO2 <=> H+ + NO (7.7)
KNO2 = K+ + NO (7.8)
KNO2 HNO2 HNO2 NO2-. , + NO , HNO2 .
[+] :
[H+] = /.
[NO ] NO , HNO2 KNO2:
[NO ] = + .
HNO2 KNO2
NO , HNO2, /, 1 HNO2 1 + 1 NO ( 7.7).
NO , NO2 : = αn = 0,2·1·1 = 0,2 / ( 7.8.),
NO2 - , α = 1, n = 1.
[NO ] = ( + 0,02) /
[HNO2] = (0,01 ) /.
= 410-4, (.)
, << 0,01 /, , , (+0,02) (0,01- ) , :
; = [H+] = 2 · 10-4 /
= -lg(210-4) = 3,7
: = 3,7
1. - :
) (III) (Cr2(SO4)3),
) (Na2S)