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# Copy of exercice condu

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``` 72
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.&amp; 8-KNO3(s)\$ A '4 [email protected] I'7 &quot;!
c = 2, 0 &times;10 mol ⋅ L−1 b;7 K \$ A 'Y f I 0 &quot;,
Y&amp; f I 0 l=1,0 cm]qS=1,0 cm&sup2;]'0 &gt; &quot;:
−3
λ NO3−
= 7,1 &times; 10 −3 S ⋅ m 2 ⋅ mol −1 . λ K + = 7,4 &times; 10 −3 S ⋅ m 2 ⋅ mol −1 )[email protected]
eau
KNO3(s) 
→ K (+aq ) +NO3(− aq ) ).&amp; 8-KNO3(s)\$ A '4 [email protected] &quot;!
σ = (λK + + λNO − ) &times; c )\$ A 'Y f &quot;,
3
c = 2, 0mol ⋅ m −3 )=J_0 mol ⋅ m −3 5 mol ⋅ L−1 # ;7 ' /0=3I
−3
−2
−1
σ == (7, 4 + 7,1).10 &times; 2 = 2,9.10 S .m )CBA
−4
S
−2 10
−4
G = σ &times; = 2,9 &times; 10 &times; −2 = 2,9 &times;10 S. )Y&amp; f &quot;:
l
10
K = ]'' f &amp; 1U L V\$ 0,05 mol.L-1b;7 6J 79Y f 1U
0,01 m
G = 10 mS
Y&amp; 9 f I 0 &quot;!
896J f&amp; r&amp; 45 7] &amp; f&amp; l''\$ &quot;,
0,005 S.m2.mol
G = K ⋅ σ ) ' [email protected] f &amp; f&amp; [email protected]&quot;!
σ =
G 0,010
=
= 1,0 S .m −1 )4
K 0,010
I'(.&amp; 8-6J 794 [email protected] [ Na + ] = [OH − ] = C 6J 79Y 8-&quot;,
NaOH ( S ) → Na(+aq ) + OH (−aq ) )=( σ = Σλi [ X i ] = λ Na &times; [ Na + ] + λOH &times; [OH − ] )9Y&amp; f @-8'
&Ugrave; σ = λ Na &times; C + λOH &times; C
&Ugrave; σ = C &times; (λ Na + λOH ) www.bestcours.net
+
−
+
−
+
λOH =
−
σ
C
−
− λ Na + &Ugrave; (λ Na + + λOH − ) =
σ
C
&Ugrave;
1,0
− 0,005 = 0,015 S ⋅ m 2 ⋅ mol −1 )CBA
50
−3
mol ⋅ m 5 mol ⋅ L−1 # ;7 ' /0= ΔχϮΤϠϣ
λOH =
−
73
[ =7/0 6 λ &amp; f&amp; c8&amp; ;7 ' σ f&amp; #R 8' [email protected] 74&quot;!
5&times;10-3 mol&middot;L-1.b;7 (Ag + + NO3- ) GN A 'Y f 25&deg;C60&quot;,
13.3 mS.m-189H'f r7 45 GN A 'Y&amp;8&amp; ;7 ' I 0 &quot;:
2
-1
+
2
-1
λ(N O3− ) = 7,14 mS.m .mol λ(Ag ) = 6,19 mS.m .mol )[email protected]
σ = λi ⋅ ci )λ &amp; f&amp; c8&amp; ;7 ' σ f&amp; #R 8' [email protected] &quot;!
i
) 89 f&amp; /0 mol ⋅ m −3 ) 89 ;7 ' /0 S.m2.mol-1 )89 λ &amp; f&amp; /0 g
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S&middot;m-1
σ = (λAg + λNO ) ⋅ c ) GN A 'Y f &quot;,
+
−
3
c = 5 mol&middot;m-3 =J- mol ⋅ m −3 5 mol ⋅ L−1 # ;7 ' /0Y
σ = (6,19 + 7,14) &times;10−3 ⋅ 5 = 6, 66 &times;10−2 S&middot;m-1 )45
c =
σ
λAg + λCl
+
=
−
0, 0133
= 1mol ⋅ m −3 = 10−3 mol ⋅ L−1 ) GN A '8&amp; ;7 ' &quot;:
−3
(6,19 + 7,14) &times; 10
Mg2+(aq) + 2 ;h&amp; A '8S Y '@
C0b;7 NO3 –(aq)
H&lt;l' Y&amp;@'\$;7 ' K9 1U L V\$ ]\$U?Y&amp; K]G f &amp;
]''
G = 0,025 S]'&amp;Ur(-K = 0,1 m
Y&amp; K9 f I 0 &quot;!
iY&amp;8&amp; ;7 ' &amp; YXL# l''\$ &quot;,
mol.m-3
60λNO3- = 0,00714 S.m2.mol-1 &amp;&quot;:
Mg2+X &amp; f&amp; &amp;U
l' &amp;H&lt;&amp; = @&amp; @60&quot;F
λMg2+λNO3- G 0,025
σ = =
= 0,25 S ⋅ m −1 )45 G = Kσ )Y&amp; f &quot;!
K
0,1
C0 = 10 3C0 = 0,010 mol.L-1 σ = 0, 25 S ⋅ m −1 f&amp; [- &amp; ;7 ' &amp;U &amp; YXL# &quot;,
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mol.m-3
C09;h&amp; A ';7 &amp;&quot;:
2+
–
[NO3 ] = 2 &times; C0[Mg ] = C0) σ = Σλi [ X i ] = λNO &times; 2C0 + λMg &times; C0 )9 f&amp; @-8'
−
2+
3
λMg =
2+
0, 25
σ
− 2 &times; 0, 00714 = 0, 011 S ⋅ m 2 ⋅ mol −1 )CBA λMg 2+ =
− 2λNO − )45
3
10
C0
x = C y = σ g y = a &times; xH'[email protected] [email protected]&amp; =f3# &amp;?[' #/ σ = f (C ) Y=E&amp;&amp; &amp; &quot;F
a = (2λNO + λMg
−
3
2+
H&lt;&amp; = @&amp; a
) )9H&lt;&amp; = @&amp; 45 σ = C &times; (2λNO + λMg ) &Ugrave; σ = λNO &times; 2C + λMg &times; C )
74
−
2+
−
3
2+
3
)# (&amp; 8' R&gt; 178- G
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0,02 mol/Lb;7 *( P&amp;0Y # 30 mLj
0,01 mol/Lb;7 6J 79Y # 10 mLj
878S&amp;( Y' '@
)[email protected]
ion
Na+
ClH3O+
HO
-3
-3
-3
-3
-1
λ Sm&sup2;mol 5,01 10 7,63 10 34,98 10 19,86 10
6J 79*( +&amp;0#=N' S&amp;( [email protected]&amp; I'7 &quot;!
JU [' &amp; =N'&amp; 60=N' [Y&lt;3&quot;,
S] Y&amp; 8-/&lt; '&amp; A ;7 I 0 &quot;:
S] 8-R&gt;σ f&amp; 60&quot;F
H
3
+
O
+
H
O
-
H 3O + + HO- → 2H 2 O )=N' [email protected] &quot;!
&quot;,
=N' [email protected]
2 H 2 O
→
n1 =0,03 &times; 0,02 = 6 10-4 mol n 2 =0,01&times; 0,01 = 10-4 mol
6 10-4 -x
10-4 -x
6 10-4 -xmax
10-4 -xmax
oIK n/ -
S / -
/ -
=N' YXL
S] )9JU [' OH 7] 9&amp; =N'&amp; - n1 = 6 10 mol n 2 = 10 mol ) &amp;
xmax=10-4 mol
) S] 8-A ;7 &quot;:
−
n [Na ]f =
+
n f ( Na + )
Vt
-4
-4
n i ( Na + ) 0,01&times; 10
=
= 2,5.10-3mol L-1 = 2,5mol.m -3 )6J ;7 j
Vt
( 30+10 )
oT N' HkV h'H6 &amp;745=N' 8- M 6J
n f ( Cl- ) n i ( Cl- ) 0,02 &times; 30
9( n [Cl ]f =
=
=
= 1,5.10-2 mol L-1 = 15mol.m -3 )( ;7 j
Vt
Vt
40
-
oT N' Lu
o =N' n OH − f =
n f ( OH
Vt
−
) = 10
−4
− xm
= 0mol / L ) 7] ;7 j
Vt
n f ( H 3O + ) 6.10-4 − xm
5.10-4
[H 3O ]f =
=
=
= 1,25.10-2 mol L-1 =12,5mol.m -3 ) 7 ;7 j
-3
Vt
Vt
40.10
+
σ = λCl . Cl − + λNa . Na + + λOH . OH − + λH O . H 3O + )&quot;F
σ =10-3 ( 34,98 &times; 12,5 + 7,63 &times;15+5,01&times; 2,5) = 0,564 S.m -1 )CBA
−
+
−
+
3
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75
=J-25&deg;C/ &lt;6 V[&amp; .&amp; 8- Fe3 ( PO4 ) 2 ,8H 2 O H&amp;&amp; II AN\$-# m '7IK
439 mS.m-1H'f Y
H&amp;&amp; II AN\$-4 [email protected] I'7 &quot;!
/&lt; '&amp; AX &amp; AXf&amp; *K7Y&amp;C;7 ' Y&amp; f @R &quot;,
Y&amp;C8&amp; ;7 ' 60&quot;:
Y&amp; K9# 1,00 L.YJ cX i K&amp; '7l''\$ &quot;F
λ PO = 27,84 mS ⋅ m 2 ⋅ mol −1 λ Fe = 10,70 mS ⋅ m 2 ⋅ mol −1 )[email protected]
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2+
3−
4
Fe3 ( PO4 ) 2 ,8H 2 O( S ) → 3 Fe(2aq+ ) + 2 PO43− ( aq ) + 8 H 2 O( L ) )H&amp;&amp; II AN\$-4 [email protected] &quot;!
σ = Σλi [ X i ] ) [email protected]&quot;,
2+
3−
PO4 Fe )&amp;9Y&amp;#&lt; '&amp; #
σ = λ Fe &times; [ Fe 2+ ] + λ PO &times; [ PO43− ] )9 f&amp; @45
2+
σ = C (3λ Fe
2+
3−
4
[ PO43− ] = 2 &times; C [ Fe 2+ ] = 3 &times; C )- ' 7' AX @&amp; '
+ 2λ PO ) &Ugrave; σ = λ Fe &times; 3C + λ PO &times; 2C )^J f&amp; @45
3−
4
2+
3−
4
σ = C (3λ Fe + 2λ PO ) )&quot;:
2+
C =
3−
4
σ
(3λ Fe 2 + + 2λ PO 3− )
)4
4
C =
0,439
= 5,00 mol ⋅ m −3 )CBA
−3
(3 &times; 10,70 ⋅ 10 + 2 &times; 27,84 ⋅ 10 )
−3
5,00 &times; 10-3 mol.L-1)-mol.L-1/0 5Y
)Y&amp; # 1,00 L.YJ cX i K&amp; '7&quot;F
M = 3 &times; M Fe + 2 &times; M P + 8 &times; M O + 8 &times; M H O )i K&amp; &amp; '( 3I M = 3 &times; 55,8 + 2 &times; 31,0 + 8 &times; 16,0 + 8 &times; 18,0 = 501 g ⋅ mol −1 )CBA
n = C &times; V)=( I'(/6&amp; &amp;7C = 5,00 &times; 10-3 mol.L-1)9i K&amp;8&amp; ;7 ' &amp;
m = C &times; V &times; M&Ugrave;m = n &times; M)89i K&amp; '7m = 5,00 &times; 10-3 &times; 1,00 &times; 501 = 2,51 g)CBA
2
)[email protected]
)25&deg;C / &lt;6 &amp; Af&amp; +
-3
2
λ(Na (aq)) = 5,01.10 S.m .mol-1;λ(HCOO-(aq)) = 5,46.10-3 S.m2.mol-1
M(C) = 12 g.mol-1 ; M(H) = 1 g.mol-1 ; M(O) = 16 g.mol-1 ; M(Na) = 23 g.mol-1 ) &amp; ='(
8-HCOONa(s)6J A E # m = 68,0 mg '7 4~8S Y&amp;V = 100,0 mL&amp;0 Gj
V[&amp; .&amp;
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.&amp; 8-6J A E 4 [email protected] I'7 &quot;!
c;7 ' I 0 M(HCOONa(s)) V ,m Y&amp;c8&amp; ;7 ' @R &quot;,
Y&amp; 8-/&lt; '&amp; [email protected] 8&amp; ;7 ' I 0 &quot;:
]'&amp;UI 0 ?c;7 ' Y&amp;σ1 f&amp; @R &quot;F
#S ' #6 '( # (' f L &amp;h?k Y&amp; 5 V[&amp; .&amp; # V’&amp;0QGj
U = 1,00 =J-S = 3,21 cm2&amp;h&amp; .; 0 L = 1,00 cm - &amp;]=JN#c ' @-/V
#'NJ #&amp;h&amp; Y&amp; 8-/ I = 2,47 mA
k &gt; '?G f &amp; I 0 &quot;x
Y&amp;σ2 f&amp; l''\$ &quot;y
QN&gt;&amp; Y&amp;c’8&amp; ;7 ' I 0 &quot;
* &lt;[email protected] V[&amp; .&amp;V’? l''\$ &quot;
76
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HCOONa(s) → HCOO-(aq) + Na+(aq)).&amp; 8-6J A E 4 [email protected] &quot;!
n
m
)Y&amp;c8&amp; ;7 ' @&quot;,
c = 0,010 mol.L-1)CBAc = =
V
(M &times; V)
)Y&amp; 8-/&lt; '&amp; [email protected] 8&amp; ;7 ' &quot;:
+
n ( Na (aq) ) = n ( HCOO (aq) ) = n ( HCOONa (s ) ) =c &times; V )=N' [email protected] YXL# [Na+(aq)] = [HCOO-(aq)] = 0,010 mol.L-1 = 10 )CBA[Na+(aq)] = [HCOO-(aq)] = c)45
mol.m-3
σ1 = λ(Na+(aq)) &times; [Na+(aq)] + λ(HCOO-(aq)) &times; [HCOO-(aq)])Y&amp;σ1 f&amp; @&quot;F
σ1 = (λ(Na+(aq)) + λ(HCOO-(aq))) &times; c)-[Na+(aq)] = [HCOO-(aq)] = c) &amp;
σ1 = (5,46.10-3 + 5,01.10-3) &times; 10 = 1,05.10-1 S.m-1)CBA
I 2,47.10-3
G = =
= 2,47.10-3 S)G f &amp; i 0&quot;x
U
1,00
L 1,00.10-2
= 31,2 m-1) k &gt; '
k= =
S 3,21.10-4
σ2 = k &times; G = 2,47.10-3 &times; 31,2 = 7,69.10-2 S.m-1)Y&amp;σ2 f&amp; &quot;y
)QN&gt;&amp; Y&amp;c’8&amp; ;7 ' &quot;
+
σ2 = (λ(Na (aq)) + λ(HCOO (aq))) &times; c’)45c’;7 'c;7 ' R[- h fFY a UX[
c’ = σ2/(λ(Na+(aq)) + λ(HCOO-(aq))))-8'
c’ = 7,69.10-2/(5,46.10-3 + 5,01.10-3) = 7,35 mol.m-3)C&quot;A
n = c’ &times; (V+ V’))-8'i K&amp; ? /6 &amp;7 h'QN&gt;' &amp;YXL) V[&amp; .&amp;V’? &quot;
-3
-3
-1
-2
V’ = 1,0.10 /7,35.10 - 1,0.10 = 3,6.10 L = 36 mL)CBAV’ = n/c’ – V)45
# &amp;h&amp; .; f (_C1b;7 6J (S1Y # 100 mL8- f L &amp;h
G1 = 1,22 mS89#6 '( #Y&amp;
.; f (_C2b;7 6J (S2Y # 100 mL8- f &amp; L`N &amp;h?
G2 = 1,44 mS89#6 '( #Y&amp; # &amp;h&amp;
C2;7 ' # hf 3 7 C1;7 ' 7 4 #i 0&quot;!
Y&amp; 8- [ f &amp; L &amp;h? S1Y # 100 mL5 V[&amp; .&amp; # 100 mLQG&quot;,
Y&amp; K]G3 f &amp; &amp;Ul''\$ C1 H=J&amp; Y&amp;C;7 ' 9 H=J&amp;
Cb;7 -(H=J&amp; Y&amp; #S2Y # 100 mLS1Y # 100 mLT;&amp;&quot;:
Y&amp;G4 f &amp; &amp;UI 0 ?C2C1#;7 ' V\$' &amp;U=E&amp;
Y&amp;C2;7 ' # hf S1Y&amp;C1;7 ' )-Y&amp; ;7 g 6 q I\$'G f &amp; &amp;&quot;!
S2
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G3. =
77
G1
C
)89Y&amp; K9 f -8' C = 1 b;7 -QJ 5QNLY&amp; &amp;&quot;,
2
2
G3 = 0,61 Ms)CBA
n n +n
C &times;V + C &times;V
C = = 1 2 = 1 1 2 2 )H=J&amp; Y&amp; ;7 &quot;:
Vt
Vt
Vt
V
C1 + C2
)- V1 = V2 = t ) &amp;
C2C1#;7 ' V\$' &amp;U=E&amp;C;7 ' -8' C =
2
2
G + G2
G4 = 1
= 1,33 mS )-Y&amp; ;7 g 6 q I\$'G f &amp; &amp;
2
+
-3
2
-l
λ(K ) = 7,35. 10 S. m .mol ; λ(Cl-) = 7,63. 10-3 S. m2.mol-l) &amp; f&amp; )[email protected]
8S Y # .;&lt; f =&lt; # =&amp;@' &amp; 8 ' I7 ' =E&amp;=(c?U&quot;!
-3
c = 5,00.10 b;7 (K+ + Cl-)\$ ((S1)8S Y # .;&lt;1 f L V\$ &quot;,
mol.L-1
I1 = 3,52 89Y&amp; 8-&amp; 8S ]( ' /-U1 = 0,800 V#'NJ 8V # ' ( mA
Y&amp; # &amp;h&amp; .;G1 f &amp; I 0 !&quot;,
U2 = 0,500 V 08-]\$U#(&amp;&amp; I2' /89 ,&quot;,
(S1)Y&amp;σ1 f&amp; I 0 [email protected]&amp; &amp; f&amp;*'@'\$:&quot;,
'E bK] V &amp; = @ 89 k &gt; ' [ O\$ # l''\$ F&quot;,
-3
-1
c = 5,00.10 mol.L b;7 ' Rb+ + Cl- ((S2)Y g [ &gt; `N=&amp;@' &quot;:
G2 = 4,53 .10-3 SH'f f&amp; l''\$ Cl-Rb+# # =( &amp; f&amp; (S2)Y&amp;σ2 f&amp; @R
λ(Rb+) &amp;
=J&amp; (S3) Y&amp;σ3 f&amp; @&lt; (S2)Y&amp; # 100 mL(S1)Y&amp; # 100 mLT;&amp;&quot;F
]'&amp;UI 0 ?σ2σ1 H
)=&amp;@' &amp; 8 ' I7 ' &quot;!
# '&amp;VN R 8 ' / 8- ' R _0
'/ &amp; 6;#08- f &amp; 1U L8V
i'
)Y&amp; # &amp;h&amp; .;G1 f&amp; !&quot;,
G1 =I1/U1 = 3,52.10-3/0,800 = 4,40.10-3 S
)- h'Y&amp;G f &amp; &amp;)I2' /,&quot;,
I2 = G1 &times; U2 = 2,2.10-3 A)4 G1 = I2/U2
)(S1)Y&amp;σ1 f&amp; :&quot;,
+
+
+
σ1 = λ(K ) &times; [K ] + λ(Cl ) &times; [Cl ] = c &times; (λ(K ) + λ(Cl-)) = 0,0749 S.m-1
k = σ1/G1 = 17,0 m-14 σ1 = k &times; G1) [email protected])k &gt; 'F&quot;,
σ2 = λ(Rb+) &times; [Rb+] + λ(Cl-) &times; [Cl-] = c &times; (λ(Rb+) + λ(Cl-)(S2)Y&amp;σ2 f&amp; @&quot;:
))
+
) λ(Rb ) &amp; f&amp;
k &times; G2
σ2 = k &times; G2 = 0,0770 S.m-1λ(Rb+) =
- λ(Cl-) =7,79.10-3 S.m2.mol-1 c
)(S3) Y&amp;σ3 f&amp; @&quot;F
78
+
+
+
+
σ3 = λ(Rb ) &times; [Rb ]’ + λ(Cl ) &times; [Cl ]’ + λ(K ) &times; [K ]’ )
)(S3)Y&amp; 8-A ;7 I [Rb ]'=
+
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n ( Rb + )
V1 + V2
[K ]'=
+
[Cl ]'=
-
=
n (K+ )
V1 + V2
n ( Cl- )
V1 + V2
=
c &times; V1
c
+
= ) Rb A ;7 j
V1 + V2 2
=
c &times; V2
c
+
= )K A ;7 j
V1 + V2 2
c &times; V1 + c &times; V2
= c )Cl A ;7 j
V1 + V2
+
λ(Rb )
λ(K+) σ1 σ2
σ3 = c &times; (
+ λ(Cl ) +
) = + = 0,0760 S.m-1)45
2
2
2 2
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```