a) PTHH: \(FeCl_3+3NaOH\rightarrow3NaCl+Fe\left(OH\right)_3\downarrow\)

                 \(2Fe\left(OH\right)_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+6H_2O\)

b) Ta có: \(n_{FeCl_3}=0,3\cdot0,5=0,15\left(mol\right)\)

\(\Rightarrow n_{NaOH}=0,45mol\) \(\Rightarrow V_{ddNaOH}=\dfrac{0,45}{0,25}=1,8\left(l\right)\)

c) Theo PTHH: \(n_{NaCl}=n_{NaOH}=0,45mol\)

\(\Rightarrow C_{M_{NaCl}}=\dfrac{0,45}{2,1}\approx0,21\left(M\right)\) 

(Coi như thể tích dd thay đổi không đáng kể)

d) Theo PTHH: \(n_{H_2SO_4}=\dfrac{3}{2}n_{Fe\left(OH\right)_3}=\dfrac{3}{2}n_{FeCl_3}=0,225mol\)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,225\cdot98}{20\%}=110,25\left(g\right)\) 

\(\Rightarrow V_{ddH_2SO_4}=\dfrac{110,25}{1,14}\approx96,71\left(ml\right)\)

\(n_{CuCl_2}=0,3.0,5=0,15mol\)

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

\(n_{Cu\left(OH\right)_2}=n_{CuCl_2}=0,15mol\)

\(m_{Cu\left(OH\right)_2}=0,15.98=14,7gam\)

\(n_{NaOH}=2n_{CuCl_2}=2.0,15=0,3mol\)

\(C_{M_{NaOH}}=\dfrac{0,3}{0,25}=1,2M\)

c) \(n_{NaOH}=\dfrac{1}{2}.0,3=0,15mol\)

-Gọi công thức muối clorua là RCl_n với n là hóa trị của R(1\(\le n\le3,\) n nguyên)

nNaOH+RCl_n\(\rightarrow\)R(OH)_n+nNaCl

\(n_{RCl_n}=\dfrac{1}{n}n_{NaOH}=\dfrac{0,15}{n}mol\)

\(M_{RCl_n}=\dfrac{7,125}{\dfrac{0,15}{n}}=47,5n\)\(\rightarrow\)R+35,5n=47,5n

\(\rightarrow\)R=12n

n=1\(\rightarrow\)R=12(loại)

n=2\(\rightarrow\)R=24(Mg)\(\rightarrow\)MgCl₂

n=3\(\rightarrow\)R=36(loại)

a) $CuSO_4 + 2NaOH \to Cu(OH)_2 + Na_2SO_4$

b) $n_{Cu(OH)_2} = n_{CuSO_4} = \dfrac{16}{160} = 0,1(mol)$
$m_{Cu(OH)_2} = 0,1.98 = 9,8(gam)$

c) $n_{NaOH} = 2n_{CuSO_4} = 0,2(mol) \Rightarrow C_{M_{NaOH}} = \dfrac{0,2}{0,1} = 2M$

PTHH: \(CuSO_4+2NaOH\rightarrow Na_2SO_4+Cu\left(OH\right)_2\downarrow\)

Ta có: \(n_{CuSO_4}=\dfrac{16}{160}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{NaOH}=0,2\left(mol\right)\\n_{Cu\left(OH\right)_2}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{NaOH}}=\dfrac{0,2}{0,1}=2\left(M\right)\\m_{Cu\left(OH\right)_2}=0,1\cdot98=9,8\left(g\right)\end{matrix}\right.\)

a. PTHH: \(CuSO_4+2NaOH--->Na_2SO_4+Cu\left(OH\right)_2\downarrow\)

b. Đổi 100ml = 0,1 lít

Ta có: \(n_{Cu\left(OH\right)_2}=\dfrac{9,8}{98}=0,1\left(mol\right)\)

Theo PT: \(n_{CuSO_4}=n_{Cu\left(OH\right)_2}=0,1\left(mol\right)\)

=> \(m_{CuSO_4}=0,1.160=16\left(g\right)\)

c. Theo PT: \(n_{NaOH}=2.n_{CuSO_4}=2.0,1=0,2\left(mol\right)\)

=> \(C_{M_{NaOH}}=\dfrac{0,2}{0,1}=2M\)

a) 

Mg + 2HCl --> MgCl₂ + H₂

Fe₂O₃ + 6HCl --> 2FeCl₃ + 3H₂O

MgCl₂ + 2KOH + 2KCl + Mg(OH)₂

FeCl₃ + 3KOH --> 3KCl + Fe(OH)₃

Mg(OH)₂ --t^o--> MgO + H₂O

2Fe(OH)₃ --t^o--> Fe₂O₃ + 3H₂O

b) Gọi số mol Mg, Fe₂O₃ là a, b (mol)

Theo PTHH: \(a=n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

Theo PTHH: \(n_{MgO}=n_{Mg}=a=0,15\left(mol\right)\)

=> \(n_{Fe_2O_3\left(chất.rắn.sau.khi.nung\right)}=\dfrac{22-0,15.40}{160}=0,1\left(mol\right)\)

Theo PTHH: \(n_{Fe_2O_3\left(bđ\right)}=n_{Fe_2O_3\left(chất.rắn.sau.khi.nung\right)}=0,1\left(mol\right)\)

=> b = 0,1 (mol)

\(\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{0,15.24}{0,15.24+0,1.160}.100\%=18,37\%\\\%m_{Fe_2O_3}=\dfrac{0,1.160}{0,15.24+0,1.160}.100\%=81,63\%\end{matrix}\right.\)

Rainbow

a,

\(Na_2CO_3+2HCl\rightarrow2NaCl+CO_2+H_2O\left(1\right)\)

\(NaOH+HCl\rightarrow NaCl+H_2O\left(2\right)\)

b,

Ta có :

\(n_{NaCl}=\frac{20,475}{58,5}=0,35\left(mol\right)\)

\(n_{Na2CO3}=\frac{10,6}{106}=0,1\left(mol\right)\)

\(\Rightarrow n_{NaCl\left(1\right)}=0,1.2=0,2\left(mol\right)\)

\(n_{NaCl}=0,35-0,2=0,15\left(mol\right)\)

\(\Rightarrow n_{NaOH}=0,15\left(mol\right)\)

\(\Rightarrow x=CM_{NaOH}=\frac{0,15}{0,3}=0,5M\)

1/ nNaCl=5,85/58,5=0,1 mol. 
nAgNO3=34/170=0,2 mol. 
PTPU: NaCl+AgNO3=>AgCl+NaNO3 
vì NaCl và AgNO3 phan ung theo ti le 1:1 (nAgNO3 p.u=nNaCl=0,1 mol) 
=>AgNO3 du 
nAgNO3 du= 0,2-0,1=0,1 mol. 
Ta tinh luong san pham theo chat p.u het la NaCl 
sau p.u co: AgNO3 du:0,1 mol; AgCl ket tua va NaCl: nAgCl=nNaNO3=nNaCl=0,1 mol.V(dd)=300+200=500ml=0,5 ()l 
=>khoi lg ket tua: mAgCl=0,1.143,5=14,35 g 
C(M)AgNO3=C(M)NaNO3=n/V=0,1/0,5=0,2 M