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Theo đề bài ta có : nHCl = 0,2.0,2=0,04(mol)
a) Ta có PTHH :
\(HCl+NaOH\rightarrow NaCl+H2O\)
0,04mol.....0,04mol....0,04mol
Ta có :
\(V_{\text{dd}HCl\left(c\text{ần}-d\text{ùng}\right)}=\dfrac{0,04}{0,1}=0,4\left(lit\right)=400\left(ml\right)\)
CMNaCl = \(\dfrac{0,04}{0,2}=0,2\left(M\right)\)
b) Theo đề bài ta có : mddHCl=\(200.1=200\left(g\right)\)
Ta có PTHH :
\(Ca\left(OH\right)2+2HCl\rightarrow CaCl2+2H2O\)
0,02mol...........0,04mol....0,02mol
Ta có :
\(m\text{dd}Ca\left(OH\right)2\left(c\text{ần}-d\text{ùng}\right)=\dfrac{0,02.74}{5}.100=29,6\left(g\right)\)
C%CaCl2 = \(\dfrac{0,02.111}{0,02.74+200}.100\%\approx1,102\%\)
Vậy..............
Theo đề bài ta có :
VddHCl=200ml=0,2 l
nHCl = 0,2.0,2=0,04 mol
a) Ta có PTHH 1:
HCl + NaOH \(\rightarrow\) NaCl + H2O
0,04mol...0,04mol....0,04mol
=> \(\left\{{}\begin{matrix}V\text{dd}NaOH=\dfrac{0,04}{0,1}=0,4\left(l\right)=400\left(ml\right)\\CM_{\text{dd}NaCl\left(c\text{ần}-d\text{ùng}\right)}=\dfrac{0,04}{0,2}=0,2\left(M\right)\end{matrix}\right.\)
b) Ta có PTHH 2 :
2HCl + Ca(OH)2 -> CaCl2 + 2H2O
0,04mol...0,02mol.....0,02mol
Ta có : mdd(sau-p/ư) = 200.1 + 0,02.74 = 201,48 g
=> C%CaCl2 = \(\dfrac{\left(0,02.111\right)}{201,48}.100\%\approx1,102\%\)
Vậy....
Bài 1:
PTHH: \(BaO+H_2SO_4\rightarrow BaSO_4+H_2O\)
Bđ____0,05___0,2
Pư____0,05___0,05_______0,05
Kt____0______0,15_______0,05
\(m_{kt}=m_{BaSO_4}=0,05.233=11,65\left(g\right)\)
\(m_{ddsaupư}=7,65+200-11,65=196\left(g\right)\)
\(C\%ddH_2SO_4=7,5\%\)
Bài 2: \(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)
bđ___0,1_______0,5
pư__1/12_______0,5_____1/6
kt ___1/60______0_______1/6
\(m_{FeCl_3}=\dfrac{1}{6}.162,5\approx27g\)
\(C_{MddFeCl_3}=\dfrac{1}{6}:0,5\approx0,3M\)
PTHH: \(H_2SO_4+2KOH\rightarrow K_2SO+2H_2O\)
Ta có: \(n_{H_2SO_4}=0,2\cdot1=0,2\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}n_{KOH}=0,4\left(mol\right)\\n_{K_2SO_4}=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{ddKOH}=\dfrac{\dfrac{0,4\cdot56}{6\%}}{1,048}\approx356,2\left(ml\right)\\C_{M_{K_2SO_4}}=\dfrac{0,2}{0,2+0,3562}\approx0,36\left(M\right)\end{matrix}\right.\)
\(n_{H_2SO_4}=1.0,2=0,2\left(mol\right)\\ H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\\ 0,2.........0,4........0,2.......0,2\left(mol\right)\\ a.m_{ddKOH}=\dfrac{0,4.56.100}{6}=\dfrac{1120}{3}\left(g\right)\\ V_{ddKOH}=\dfrac{\dfrac{1120}{3}}{1,048}=\dfrac{140000}{393}\left(ml\right)\approx0,356\left(l\right)\)
\(b.C_{MddK_2SO_4}=\dfrac{0,2}{\dfrac{140000}{393}+0,2}\approx0,00056\left(M\right)\)
\(n_{CO_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
PT: \(CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3+H_2O\)
Theo PT: \(n_{Ca\left(OH\right)_2}=n_{CaCO_3}=n_{CO_2}=0,25\left(mol\right)\)
a, \(C_{M_{Ca\left(OH\right)_2}}=\dfrac{0,25}{0,1}=2,5\left(M\right)\)
b, \(m_{CaCO_3}=0,25.100=25\left(g\right)\)
c, \(Ca\left(OH\right)_2+2HCl\rightarrow CaCl_2+2H_2O\)
Theo PT: \(n_{HCl}=2n_{Ca\left(OH\right)_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,5.36,5}{20\%}=91,25\left(g\right)\)
a)PTHH:
HCl + NaOH → NaCl + H2O
nHCl = 0,04 (mol) = nNaOH = nNaCl
=>VddNaOH = 0,04/0,1 = 0,4 (l) = 400 (ml)
Vdd = VddNaOH + VddHCl = 0,6 (l)
=>C(M) ≈ 0,067 (M)
b) 2HCl + Ca(OH)2 → CaCl2 + 2H2O
nCa(OH)2 = nCaCl2 = (1/2)nHCl = 0,02 (mol)
(Nồng độ phần trăm = 25% ????)
mCa(OH)2 = 1,48 (g)
=>mdd(Ca(OH)2) = 5,92 (g)
mddHCl = 220 (g)
=>mdd = 225,92 (g)
mCaCl2 = 2,22 (g)
=>%mCaCl2 ≈ 0,98%
nồng độ phần trăm = 5%