để trung hòa 125ml dd Ca(OH)2 cần dùng 182,5g HCl 10%. tính \(C_{M_{Ca\left(OH\right)_2}}\)
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\(n_{CO_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
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: \(n_{HCl}=2n_{Ca\left(OH\right)_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,5.36,5}{20\%}=91,25\left(g\right)\)
\(n_{NaOH}=0,25.V\left(mol\right)\)
\(n_{Ca\left(OH\right)_2}=0,5.V\left(mol\right)\)
=> \(n_{OH^-}=0,25.V+2.0,5.V=1,25V\left(mol\right)\)
\(n_{HCl}=0,55.2=1,1\left(mol\right)=>n_{H^+}=1,1\left(mol\right)\)
H+ + OH- --> H2O
1,1->1,1
=> 1,25.V = 1,1
=> V = 0,88(l)
\(n_{Ca} = a(mol)\\ Ca + 2H_2O \to Ca(OH)_2 + H_2\\ n_{H_2} = n_{Ca(OH)_2} = n_{Ca} = a(mol)\\ m_{dd\ sau\ pư} = 40a + 200 - 2a = 200 + 38a(gam)\\ C\%_{Ca(OH)_2} = \dfrac{74a + 200.1\%}{200 + 38a}.100\% = 2\%\\ \Rightarrow a = \dfrac{50}{1831} \to m_{Ca} = \dfrac{2000}{1831} =1,09(gam)\)
a)\(CaCO_3-^{t^o}\rightarrow CaO+CO_2\)
\(n_{CaCO_3}=\dfrac{40.80\%}{100}=0,32\left(mol\right)\)
\(n_{CO_2}=n_{CaCO_3}=0,32\left(mol\right)\)
b) \(CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3+H_2O\)
\(n_{Ca\left(OH\right)_2}=n_{CO_2}=0,32\left(mol\right)\)
=> \(m_{ddCa\left(OH\right)_2}=\dfrac{0,32.74}{0,5\%}=4736\left(g\right)\)
Ta có: \(m_{HCl}=146.5\%=7,3\left(g\right)\Rightarrow n_{HCl}=\dfrac{7,3}{36,5}=0,2\left(mol\right)\)
PT: \(Ca\left(OH\right)_2+2HCl\rightarrow CaCl_2+2H_2O\)
Theo PT: \(n_{Ca\left(OH\right)_2}=\dfrac{1}{2}n_{HCl}=0,1\left(mol\right)\)
\(\Rightarrow V_{ddCa\left(OH\right)_2}=\dfrac{0,1}{2}=0,05\left(l\right)=50\left(ml\right)\)
Ca(OH)2+2HCl----->CaCl2 +2H2O
m\(_{HCl}=\frac{182,5.10}{100}=18,25\left(g\right)\)
n\(_{HCl}=\frac{18,25}{36,5}=0,5\left(mol\right)\)
Theo pthh
n\(_{Ca\left(OH\right)2}=\frac{1}{2}n_{HCl}=0,25\left(mol\right)\)
C\(_{M\left(Ca\left(OH\right)2\right)}=\frac{0,25}{0,125}=2\left(M\right)\)
mHCl =18,25 g =>mHCl = 0,5(mol)
PTHH: Ca(OH)2 +2HCl--->CaCL2+2H2O
=>nCa(OH)2 = 0,25 (mol)
=>CM = 0,25 / 0,125 = 2(M)