, , NH4OH:
NH4OH Û NH4+ + OH-
a [OH-] = [NH4+] = a × 0 = , (5.10)
0 , . ; b ( base ).
, ( ) , , . . , , +.
:
H2O Û H+ + OH-,
:
. = ;
. 22 0 . 1,810-16; , , :
.
:
[+][-]=10-14 w: [OH-][H+]= w =10-14 (5.11)
w 10-14. w , . , , 100 0 w =10-12.
w , (5.11), + - :
.
:
, [+]=[-] =10-7 /3, .
[H+] > [OH-] > 10-7 /3 (>10-6...10-1/3) , [H+] < [OH-] < 10-7/3 (<10-8...10-14 /3).
, .
, :
= -lg[H+].
:
= -lg[OH-].
[OH-][H+]=w=10-14 ( 220). , :
|
|
+ = 14 (5.12)
= = 7,0; < 7,0; > 7,0. 0 14.
1. 0,1 /3 .
:
Na2SO4→2Na+ + SO42-
c [ ]: 0,1 0,2 0,1
: 0,1 /3 Na2SO4 0,3 /3.
2. -, 0,1 /3 ( b =1,7610-5).
: NH3 + H2O Û NH4OH Û NH4+ + OH-
: [-]=1,3210-3; =2,88; =11,12.
3. 1,75 10-5. , 300 3 0,1 /3 , 100 .
0,1 /3 CH3COOH:
.
CH3COONa H+ 100 ( ), .. 1,32 ∙ 10-5 /3. 1 3 , x - , : [H+] = 1,32×10-5 /3
[CH3COO-] = (x + 1,32 ∙ 10-5) /3 x /3
[CH3COOH] = 0 [H+] = 0.1 1.32× 10-5 0,1 /3
, :
x = 0,133 , (CH3COONa) = 0,133 /3.
300 3 :
m (CH3COONa) = (CH3COONa) × V - × M (CH3COONa) = 0,133 × 0,3 × 82 = 3,27
: m (CH3COONa) = 3,27 .