Laborator._praktikum_po_obschej_himii
.pdf3. ,
100,174° .
0,512. |
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t . = 100,174° |
= m, m= |
m . . |
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1000 |
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m |
. . 1000 |
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= 0,512 |
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M . . |
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. . m |
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100 m = (100–m .); |
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(CO(NH2)2) = 60 |
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: % . |
= 100,174 – 100 = 0,174° |
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0,174 |
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0,512 m |
. .1000 |
m .. |
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(100 m . . ) 60 |
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m .=2 . . 100 – 2 2%. |
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: 2% |
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( , , ) -
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91
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: H2SO4, HNO3, HCl, HClO4). : 30%
(H3PO4, HF). : 2% ( , -
: H2CO3, H2SiO3, H2S ).
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( – 81, – 25, – 21). ( . -
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K+ + – |
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K |
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[K ][A ] |
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(7.14) |
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[KA] |
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K – .
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92
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K |
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(7.15) |
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1 |
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<< 1, : |
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K = 2 |
(7.16) |
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K |
(7.17) |
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(7.15, 7.17) .
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= f+ +,
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f+ f– – (
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/1000 .
93
.
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-
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H2S H+ + HS–,
HS– H+ + S2–,
Mg(OH)2 MgOH+ + OH–,
MgOH+ Mg2+ + OH–.
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1. , ,
( , , -), (SO2, CO2).
ZnS + 2HCl = ZnCl2 + H2 ,
ZnS + 2H+ = Zn2+ + H2 .
2. , -
, .
CaCl2 + K2CO3 = CaCO3 + 2NaNO2,
Ca2+ + CO32– = CaCO3 .
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94
CaCO3 Ca2+ + CO32–
= [Ca2+] [CO32–] = 4,8 10–9
3.-
:
1) ( , , .):
CH3COONa + HCl = CH3COOH + NaCl,
CH3COO– + H+ = CH3COOH. 2) :
CuSO4 + 2NaOH = Cu(OH)2 + Na2SO4,
Cu2+ + 2OH– = Cu(OH)2 .
3) ( ,
):
Zn(OH)2 + 2KOH = K2[Zn(OH)4], Zn(OH)2 +2OH– = [Zn(OH)4]2–.
4) :
KOH + HNO3 = KNO3 + H2O,
OH– + H+ = H2O.
.
:2 + + –,
K = [H+][OH–]/[H2O].
, , -
K ,
10–14.
K = [H+][OH–] = 10–14 |
(7.19) |
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–
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= -lg[H+] |
(7.20) |
-10–7 . ,
7. = 7 – .
, 7 ( pH 7 –
). – 7 ( 7 ).
95
, -
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. -
HInd IndOH,
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–
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< 3,4) [ ( 3,4–4,7), ( 4,7–6,2), -
( 6,2–7,2), (7,2–8,5)] ( > 8,5).
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– ( . 7.4). -
0 14 0,01 .
. 7.4. -001:
1 – , 2 – , 3 – -
, 4 – , 5 – (
), 6 –
, -
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. -
, , 3 + 3 K
, , NH4OH + NH4Cl.
( ) -
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.
96
5) – ,
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+ –, -
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,
, , KCl.
, -, , CH3COONa -
: CH3COO– +H2O CH3OOH + OH–.
– -
–, . -
,
(HSO3–, HPO42–, H2PO4–, HCO3–), -
, .
, -
: NH4+ +H2O NH4OH + H+.
,
(CuOH+, FeOH2+, Fe(OH)2+, ZnOH+), -
, , -
, .
,
.
. ,
.
NH4F +H2O NH4OH + HF
NH4+ + H2O NH4OH + H+
F– + H2O HF + OH–.
-
7.2. |
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. – , |
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, , [H+] = 8,32 10–4 . |
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: pH= -lg[H+] |
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[H+] = 8,32 10–4 |
pH = -lg8,32 10–4 = -(lg8,32 + lg10–4) |
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= -(0,92 – 4) = 3,08; pH 7 |
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: [OH–], pH, |
K = [H+][OH–] = 10–14 |
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pOH, . |
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10 14 |
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10 14 |
-11 |
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1,2 10 |
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8,32 10 4 |
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= -lg[OH–]; pOH= -lg1,2 10–11= -(lg1,2+lg10–11) = -(0,08-11) = 10,92
: + = 14; 3,08 + 10,92 = 14
: [OH–] = 1,2 10–11 ; = 10,92; = 3,08; .
97
7.2
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(HCl) |
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(HCN) |
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AlCl3 |
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Al(CN)3 |
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[Al(OH) |
AlCl3 + HOH Al(OH)Cl2 + HCl |
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Al(CN)3 + HOH |
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Al(OH)Cl2 + HOH |
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; pH |
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Al(OH)(CN)2 |
+ HCN |
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Al(OH)2Cl + HCl |
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Al(OH)(CN)2 + HOH |
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Al(OH)2CN + HCN |
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3 |
Al(OH)Cl2, Al(OH)2Cl. |
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Al(OH)2(CN) + HOH |
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; < 7. |
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Al(OH)3 + HCN |
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Al(OH)(CN)2, Al(OH)2CN, Al(OH)3 |
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HCN. |
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Ba l2 |
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Ba(CN)2 |
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2 |
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[Ba(OH) |
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Ba(CN)2 + HOH |
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Ba(OH)(CN) + HCN |
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: Ba(OH)CN, HCN. |
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; pH > 7 |
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). |
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NH4Cl |
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NH4CN |
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(NH |
NH4Cl + HOH NH4OH + HCl |
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NH4CN + HOH NH4OH + HCN |
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OH) |
: NH4OH, HCl. |
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: NH4OH, HCN. |
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4 |
- |
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; |
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; pH < 7. |
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NaCl |
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NaCN |
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(NaOH) |
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NaCN + HOH NaOH + HCN |
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: NaOH, HCN. |
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; > 7. |
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98
(H2SO4) |
(H2S) |
Al2(SO4)3 |
Al2S3 |
Al2(SO4)3 + 2HOH 2Al(OH)SO4 + H2SO4 |
Al2S3 + 2HOH 2Al(OH)S + H2S |
: Al(OH)SO4 |
Al(OH)S + 2HOH Al(OH)3 + H2S |
H2SO4. |
: Al(OH)S, Al(OH)3 H2S. |
; < 7. |
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BaSO4 |
BaS |
, . |
2BaS + 2HOH Ba(HS)2 + Ba(OH)2 |
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: Ba(HS)2, Ba(OH)2. |
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; > 7 ( - |
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). |
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(NH4)2SO4 |
(NH4)2S |
(NH4)2SO4 + 2HOH 2NH4OH + H2SO4 |
(NH4)2S + 2HOH 2NH4OH + H2S |
: NH4OH H2SO4. |
: NH4OH, H2S. |
; < 7. |
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Na2SO4 |
Na2S |
. |
Na2S + HOH NaOH + NaHS |
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: NaOH, NaHS. |
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; > 7. |
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99
.
, ,
5·10–9 (5 ).
,
. -
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1000 (10–6 ) ;
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1 500 (10–9 – 5 10–7 ).
-
( . 7.3).
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7.3 |
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, (1 |
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1 ). |
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10 , 1 3
100 2.
– ( . 7.5).
-, . -
100