n_AgNO3=0,05(mol)

n_HCl=0,02(mol)

n_Br,I=0,05-0,02=0,03(mol)

Ta có:

\(\left\{{}\begin{matrix}n_{KBr}+n_{NaI}=0,03\\119n_{KBr}+150n_{NaI}=3,88\end{matrix}\right.\)

n_KBr=0,02;n_NaI=0,01

%m_KBr(A)=\(\frac{119.0,02}{3,88}.100\%=61,34\%\)

=>%m_NaI(A)=100-61,34=38,66%

PTHH: AgNO₃ + HCl --> AgCl \(\downarrow\) + HNO₃ (1)

HNO₃ + NaOH --> NaNO₃ + H₂O (2)

Ta có: n_AgCl = \(\dfrac{4,305}{143,5}\) = 0,03 mol

n_NaOH = \(0,04.2=0,08\) mol

Theo PT (1): n_HCl = n_HNO3 = n_AgCl = 0,03 mol

=> C_M của HCl = \(\dfrac{0,03}{0,1}\) = 0,3M

Theo PT(2) : n_HNO3 = n_NaOH = 0,08 mol

Mà n_HNO3 (2) = n_HNO3 ban đầu + n_HNO3 (1)

=> n_HNO3 ban đầu = 0,08 - 0,03 = 0,05 mol

=> C_M của HNO₃ ban đầu = \(\dfrac{0,05}{0,1}\) = 0,5M

Vậy ...........................................

0,1 ở đâu ra z b

a/pthh: HCl + AgNO3-----> AgCl + HNO3 (1)
2AgCl + 2NaOH--------> Ag2O + 2NaCl + H2O
b/ theo bài ra ta có:
nAgCl = 4,305/143,5 = 0,03(mol)
nNaOH = 0,04 * 2 = 0,08(mol)
pthh : 2AgCl + 2NaOH--------> Ag2O + 2NaCl+ H2O
2(mol) 2(mol)
0,03(mol) 0,08(mol)
------> 0,03/2 < 0,08/2------> nNaOH dư
=> nAgCl = 0,03( mol)
theo pt (1) ta có:
nHCl = nAgCl = 0,03( mol)
=>CM(HCl) = 0,03/0,1 = 0,3(M)

cho cac axit :HCLO,HNO3,H2S,H2SO3,HNO2,HCLO4,HMno4.so axit manh la

a)

$Fe +H_2SO_4 \to FeSO_4 + H_2$

$FeSO_4 + 2KOH \to Fe(OH)_2 + K_2SO_4$
$4Fe(OH)_2 + O_2 \xrightarrow{t^o} 2Fe_2O_3 + 4H_2O$

$n_{Fe_2O_3} = \dfrac{20}{160} = 0,125(mol)$

Theo PTHH : $n_{Fe} = 2n_{Fe_2O_3} = 0,25(mol)$
$m_{Fe} = 0,25.56 = 14(gam)$

b)

$n_{H_2} = n_{Fe} = 0,25(mol)$
$V_{H_2} = 0,25.22,4 = 5,6(lít)$
c)

$n_{H_2SO_4} = n_{Fe} = 0,25(mol)$
$V_{dd\ H_2SO_4} = \dfrac{0,25}{1} = 0,25(lít) = 250(ml)$

\(PTHH:Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ FeSO_4+2KOH\rightarrow Fe\left(OH\right)_2+K_2SO_4\\4 Fe\left(OH\right)_2+O_2\underrightarrow{t^o}2Fe_2O_3+4H_2O\)

\(a.n_{Fe_2O_3}=\dfrac{20}{160}=0,125\left(mol\right)\\ n_{H_2}=n_{H_2SO_4}=n_{Fe}=n_{FeSO_4}=n_{Fe\left(OH\right)_2}=\dfrac{4}{2}.0,125=0,25\left(mol\right)\\ m_{Fe}=0,25.56=14\left(g\right)\\ b.V_{H_2\left(đktc\right)}=0,25.22,4=5,6\left(l\right)\\ c.V_{ddH_2SO_4}=\dfrac{0,25}{1}=0,25\left(l\right)=250\left(ml\right)\)

\(n_{KOH}=\dfrac{22,4}{56}=0,4(mol)\\ a,PTHH:MgCl_2+2KOH\to Mg(OH)_2\downarrow+2KCl\\ Mg(OH)_2\buildrel{{t^o}}\over\to MgO+H_2O\\ b,\text {Vì } \dfrac{n_{MgCl_2}}{1}<\dfrac{n_{KOH}}{2} \Rightarrow \text {KOH dư}\\ \Rightarrow n_{MgO}=n_{Mg(OH)_2}=n_{MgCl_2}=0,15(mol)\\ \Rightarrow m_{MgO}=0,15.40=6(g)\\ c,\text {Chất tan trong nước lọc là KCl}\\ \text {Theo PT: }n_{KCl}=2n_{MgCl_2}=0,3(mol)\\ \Rightarrow m_{KCl}=0,3.74,5=22,35(g)\)

cảm ơn bạn

Cho e hỏi công thức dùng để tính ra số mol KOH 

a) HCl + AgNO₃➞AgCl↓ + HNO₃
HNO₃ + NaOH ➞NaNO₃ + H₂O
b) n ↓ = n _AgCl = 0,03 (mol)

➞ n _HCl = 0,03 (mol)

➜ CM HCl = \(\frac{0,03}{0,1}\) = 0,3(M)
n _NaOH = 0,08(mol)
HNO₃ + NaOH ➞ NaNO₃ + H₂O
0,08 ←0,08
HCl + AgNO₃ => AgCl↓ + HNO₃
0,03 -----------------------------> 0,03
=> \(n_{HNO_3}\) ban đầu = 0,08 - 0,03 = 0,05 ➞ C_M HNO₃ = \(\frac{0,05}{0,1}\) = 0,5 (M)