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\(n_{K2O}=\dfrac{9,4}{94}=0,1\left(mol\right)\)
Pt : \(K_2O+H_2O\rightarrow2KOH|\)
1 1 2
0,1 0,2
a) \(n_{KOH}=\dfrac{0,1.2}{1}=0,2\left(mol\right)\)
200ml = 0,2l
\(C_{M_{ddKOH}}=\dfrac{0,2}{0,2}=1\left(M\right)\)
b) Pt : \(KOH+HCl\rightarrow KCl+H_2O|\)
1 1 1 1
0,1 0,1
\(n_{HCl}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)
\(m_{HCl}=0,1.36,5=3,65\left(g\right)\)
\(m_{ddHCl}=\dfrac{3,65.100}{10}=36,5\left(g\right)\)
c) \(CO_2+2KOH\rightarrow K_2CO_3+H_2O|\)
1 2 1 1
0,05 0,1
\(n_{CO2}=\dfrac{0,1.1}{2}=0,05\left(mol\right)\)
\(V_{CO2\left(dktc\right)}=0,05.22,4=1,12\left(l\right)\)
Chúc bạn học tốt
1. \(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\)
PTHH: Na2O + H2O → 2NaOH
Mol: 0,25 0,5
\(C_{M_{ddNaOH}}=\dfrac{0,5}{0,5}=1M\)
2.
PTHH: 2NaOH + H2SO4 → Na2SO4 + 2H2O
Mol: 0,5 0,25
\(m_{ddH_2SO_4}=\dfrac{0,25.98.100}{20}=122,5\left(g\right)\)
\(V_{ddH_2SO_4}=\dfrac{122,5}{1,14}=107,456\left(ml\right)\)
\(n_{Na2O}=\dfrac{m_{Na2O}}{M_{Na2O}}=0,25\left(mol\right)\)
\(Na_2O+H_2O\rightarrow2NaOH\)
0,25 mol - 0,25 mol - 0,5 mol
a) \(C_{M_{NaOH}}=\dfrac{n_{NaOH}}{V_{NaOH}}=1\left(M\right)\)
b) \(H_2SO_4+2NaOH\rightarrow Na_2SO4+2H_2O\)
0,25 mol - 0,5 mol - 0,25 mol - 0,5 mol
\(m_{ctH2SO4}=n_{H2SO4}.M_{H2SO4}=24,5\left(g\right)\)
\(C_{\%_{H2SO4}}=\dfrac{m_{ctH2SO4}}{m_{ddH2SO4}}.100\%\)
\(\Rightarrow m_{ddH2SO4}=\dfrac{m_{ctH2SO4}.100\%}{C_{\%_{H2SO4}}}=122,5\left(g\right)\)
\(D_{H2SO4}=\dfrac{m_{ddH2SO4}}{V_{H2SO4}}\Rightarrow V_{H2SO4}=\dfrac{m_{ddH2SO4}}{D_{H2SO4}}\approx107,46\left(ml\right)\)
1)
\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)
PTHH: 2Al + 3H2SO4 --> Al2(SO4)3 + 3H2
____0,1----->0,15
=> mH2SO4 = 0,15.98 = 14,7(g)
=> \(C\%=\dfrac{14,7}{250}.100\%=5,88\%\)
2)
\(n_{Na_2CO_3}=\dfrac{21,2}{106}=0,2\left(mol\right)\)
PTHH: Na2CO3 + 2HCl --> 2NaCl + CO2 + H2O
_______0,2------------------------------>0,2
=> VCO2 = 0,2.22,4 = 4,48(l)
3)
\(n_A=\dfrac{18,4}{M_A}\left(mol\right)\)
PTHH: 2A + Cl2 --to--> 2ACl
____\(\dfrac{18,4}{M_A}\)---------->\(\dfrac{18,4}{M_A}\)
=> \(\dfrac{18,4}{M_A}\left(M_A+35,5\right)=46,8=>M_A=23\left(Na\right)\)
4)
nHCl = 0,2.3 = 0,6(mol)
PTHH: M + 2HCl --> MCl2 + H2
____0,3<-----0,6
=> \(M_M=\dfrac{7,2}{0,3}=24\left(Mg\right)\)
a+b) PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\uparrow\)
Ta có: \(n_{CaCO_3}=\dfrac{10}{100}=0,1\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}n_{HCl}=0,2\left(mol\right)\\n_{CO_2}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{HCl}=0,2\cdot36,5=7,3\left(g\right)\\V_{CO_2}=0,1\cdot22,4=2,24\left(l\right)\end{matrix}\right.\)
c) Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=0,1\left(mol\right)\\n_{NaOH}=\dfrac{50\cdot40\%}{40}=0,5\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\) Tạo muối trung hòa, bazơ dư, tính theo CO2
Bảo toàn Cacbon: \(n_{Na_2CO_3}=n_{CO_2}=0,1\left(mol\right)\) \(\Rightarrow m_{Na_2CO_3}=0,1\cdot106=10,6\left(g\right)\)
a, \(Na_2O+H_2O\rightarrow2NaOH\)
\(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\)
Theo PT: \(n_{NaOH}=0,25.2=0,5\left(mol\right)\)
\(\Rightarrow C_{M_{NaOH}}=\dfrac{0,5}{0,5}=1\left(M\right)\)
b, \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)
Theo PT: \(n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}=0,25\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4}=0,25.98=24,5\left(g\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{24,5}{20\%}=122,5\left(g\right)\)
\(\Rightarrow V_{ddH_2SO_4}=\dfrac{122,5}{1,14}\approx107,5\left(ml\right)\)
a) \(BaO+H_2O\rightarrow Ba\left(OH\right)_2\)
\(n_{Ba\left(OH\right)_2}=n_{BaO}=0,15\left(mol\right)\)
\(n_{BaCO_3}=\dfrac{23,64}{197}=0,12\left(mol\right)\)
Bảo toàn nguyên tố Ba => \(n_{Ba\left(HCO_3\right)_2}=0,15-0,12=0,03\left(mol\right)\)
Bảo toàn nguyên tố C: \(n_{CO_2}=0,12+0,03.2=0,18\left(mol\right)\)
=> \(V_{CO_2}=0,18.22,4=4,032\left(l\right)\)
b)Bảo toàn nguyên tố C : \(n_{CO_2}=n_{MgCO_3}+n_{CaCO_3}=a\left(mol\right)\)
Ta có : \(\dfrac{18,4}{100}< a< \dfrac{18,4}{84}\)
=> \(0,184< a< 0,22\)
\(n_{OH^-}=0,15.2=0,3\left(mol\right)\)
Lập T: \(\dfrac{0,3}{0,22}< T< \dfrac{0,3}{0,184}\)
=>\(1,36< T< 1,63\)
Do 1< \(1,36< T< 1,63\) <2
=> Phản ứng luôn tạo kết tủa
\(13,n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\\ PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\\ .....0,3.....0,6......0,3......0,3\left(mol\right)\\ V_{H_2\left(đktc\right)}=0,3\cdot22,4=6,72\left(l\right)\\ 14,n_{CaCO_3}=\dfrac{25}{40+12+16\cdot3}=0,25\left(mol\right)\\ PTHH:CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\\ .....0,25.....0,5......0,25......0,25......0,25\left(mol\right)\\ V_{CO_2\left(đktc\right)}=0,25\cdot22,4=5,6\left(l\right)\)
6,2/62 chứ em??