a, \(CuCl_2+2NaOH\rightarrow2NaCl+Cu\left(OH\right)_2\)

\(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)

b, \(n_{CuCl_2}=\dfrac{27}{135}=0,2\left(mol\right)\)

Theo PT: \(n_{CuO}=n_{Cu\left(OH\right)_2}=n_{CuCl_2}=0,2\left(mol\right)\)

\(\Rightarrow m_{CuO}=0,2.80=16\left(g\right)\)

c, \(n_{NaOH}=2n_{CuCl_2}=0,4\left(mol\right)\)

\(\Rightarrow C\%_{NaOH}=\dfrac{0,4.40}{200}.100\%=8\%\)

gọi a, b lần lượt là số mol MgCl₂ và CuCl₂ trong 25g hỗn hợp

ta có: n_AgCl= \(\dfrac{17,22}{143,5}\)= 0,12( mol)

PTPU

MgCl₂+ 2AgNO₃\(\rightarrow\) Mg(NO₃)₂+ 2AgCl\(\downarrow\)

..a......................................................2a...... mol

CuCl₂+ 2AgNO₃\(\rightarrow\) Cu(NO₃)₂+ 2AgCl\(\downarrow\)

..b...................................................2b...... mol

MgCl₂+ 2NaOH\(\rightarrow\) Mg(OH)₂\(\downarrow\)+ 2NaCl

..a.............................a.............................. mol

CuCl₂+ 2NaOH\(\rightarrow\) Cu(OH)₂+ 2NaCl

..b.............................b......................... mol

Mg(OH)₂\(\xrightarrow[]{to}\) MgO+ H₂O

..a....................a................. mol

Cu(OH)₂\(\xrightarrow[]{to}\) CuO+ H₂O

..b...................b............... mol

ta có hệ pt

\(\left\{{}\begin{matrix}2a+2b=0,12\\40a+80b=3,8\end{matrix}\right.\)

\(\Rightarrow\) \(\left\{{}\begin{matrix}a=0,025\\b=0,035\end{matrix}\right.\)

\(\Rightarrow\) C%_MgCl2= \(\dfrac{0,025.95}{25}\).100%= 9,5%

C%_CuCl2= \(\dfrac{0,035.135}{25}\). 100%= 18,9%

cảm ơn nhaaaa

a, \(MgCl_2+2NaOH\rightarrow Mg\left(OH\right)_2+2NaCl\)

\(Mg\left(OH\right)_2\underrightarrow{t^o}MgO+H_2O\)

b, \(n_{MgCl_2}=0,2.0,25=0,05\left(mol\right)\)

 Theo PT: \(n_{MgO}=n_{Mg\left(OH\right)_2}=n_{MgCl_2}=0,05\left(mol\right)\)

\(\Rightarrow m_{MgO}=0,05.40=2\left(g\right)\)

c, \(n_{NaOH}=2n_{MgCl_2}=0,1\left(mol\right)\)

\(\Rightarrow m_{ddNaOH}=\dfrac{0,1.40}{15\%}=\dfrac{80}{3}\left(g\right)\)

BÀI7 Goi so mol MgCo3,BaCO3,MgCl2 co trong hon hp ban dau lan luot la a,b,c(mol)
MgCO3+2HCl-->MgCl2+CO2+H2O
a_____________a_____a (mol)
BaCO3+2HCl-->BaCl2+CO2+H2O
b_____________b____b (mol)
(Khi A:CO2(a+b mol)_ Dung dich B:MGCl2(a+c mol)va BaCl2:b mol)
MgCl2+2NaOH-->Mg(OH)2+2NaCl
a+c___________a+c_____2(a+c) (mol)
dung dich C:NaCL(a+b mol), BaCl2 (b mol)
Ket tua D:Mg(OH)2
Mg(OH)2 --t*->MgO+H2O
a+c________a+c (mol)
Chat ran E:MgO
CO2+Ca(Oh)2-->CaCO3+ H2O (1)

2Co2+Ca(OH)2-->Ca(HCO3)2 (2)

ta co :a+c= nMgO= 0,6/40=0,015(mol)
n Ca(Oh)2(1)=n CaCO3=0,5/100=0,005(mol)
nCa(Oh)2=0,5.o,o2=0,01(mol)
nCa(OH) (1)=0,01-0,005=0,005(mol)
=>a+b=nCO2=0,005+2.0,005=0,015(mol)
Thay a+b=0,015=>mNaCl=0,015.2.58,5=1,755(g)
=mBaCl2=3,835-1,755= 2,08(g)
=>nBaCl2=b=2,08/208=0,01(mol)
=>a=0,005(mol):c=0,01(mol)
=>mMgCO3=0,42(g)
mBaCO3=1,97(g)
mMgCl2(0,95(g)
mhh=3,34(g)

Bài 5:

Đặt a , b lần lượt là số mol của \(FeCO_3,FeO\) và \(MgO,MgCO_3\)

Theo bài ra ta có :

\(C\%_{MgSO_4}=\frac{2b.120}{\left(2a+2b\right).98:9,8\%+112a+72a+40b+84b-44.\left(a+b\right)}.100=3,76\%\)

=> a=1,8b

=> thế vào rồi tính C%

PTHH: \(CuCl_2+2NaOH\rightarrow2NaCl+Cu\left(OH\right)_2\downarrow\)

            \(Cu\left(OH\right)_2\xrightarrow[]{t^o}CuO+H_2O\)

Ta có: \(n_{CuCl_2}=0,2\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}n_{Cu\left(OH\right)_2}=0,2\left(mol\right)=n_{CuO}\\n_{NaOH}=0,4\left(mol\right)=n_{NaCl}\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{Cu\left(OH\right)_2}=0,2\cdot98=19,6\left(g\right)\\m_{CuO}=0,2\cdot80=16\left(g\right)\\m_{NaCl}=0,4\cdot58,5=23,4\left(g\right)\\C\%_{NaOH}=\dfrac{0,4\cdot40}{200}\cdot100\%=8\%\end{matrix}\right.\)

C → + O 2 A C O C O 2 → + F e O , t 0 B : C O 2 → + C a ( O H ) 2 K : C a C O 3 D :   C a H C O 3 2 C F e F e O → + H C l H 2 E : F e C l 2 → + N a O H F : : F e O H 2 → t 0 , k k G : F e 2 O 3

⇒ Chọn A.

a)2NaOH+H2SO4→Na2SO4+2H2O(1)

Cu(NO3)2+2NaOH→Cu(OH)2+2NaNO3(2)

Cu(OH)2→CuO+H2O(3)

nCuO=\(\dfrac{1,6}{80}\)=0,02mol

mddNaOH=31,25×1,12=35g

nNaOH=35×16%40=0,14mol

nNaOH(2)=0,02×2=0,04mol

⇒nNaOH(1)=0,14−0,04=0,1mol

nH2SO4=0,12=0,05mol

CM(H2SO4)=\(\dfrac{0,05}{0,05}\)=1M

CM(Cu(NO3)2)=\(\dfrac{0,02}{0,05}\)=0,4M

b)nCu=\(\dfrac{2,4}{64}\)=0,0375mol

nH+=2nH2SO4=0,1mol

nNO3−=2nCu(NO3)2=0,04mol

Cu+4H++NO3−→Cu2++NO+2H2O

\(\dfrac{0,04}{1}\)>\(\dfrac{0,03751}{1}\)>\(\dfrac{0,1}{4}\)⇒ Tính theo ion H+nNO=0,14=0,025mol

⇒VNO=0,025×22,4=0,56l