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\(n_{CO2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
a) Pt : \(CO_2+2KOH\rightarrow K_2CO_3+H_2O\)
\(n_{KOH}=2n_{CO2}=2.0,05=0,1\left(mol\right)\Rightarrow C_{MddKOH}=\dfrac{0,1}{0,1}=1M\)
Bài 8:
\(n_{H_2}=\dfrac{7,437}{24,79}=0,3\left(mol\right)\)
PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
_____0,2______0,6_____0,2____0,3 (mol)
a, \(m_{Al}=0,2.27=5,4\left(g\right)\)
b, \(C_{M_{HCl}}=\dfrac{0,6}{0,3}=2\left(M\right)\)
c, \(C_{M_{AlCl_3}}=\dfrac{0,2}{0,2}=1\left(M\right)\)
Bài 9:
Ta có: \(n_{H_2}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\)
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(MgO+2HCl\rightarrow MgCl_2+H_2O\)
a, \(n_{Mg}=n_{H_2}=0,1\left(mol\right)\Rightarrow m_{Mg}=0,1.24=2,4\left(g\right)\)
\(\Rightarrow m_{MgO}=8,4-2,4=6\left(g\right)\)
b, \(n_{MgO}=\dfrac{6}{40}=0,15\left(mol\right)\)
Theo PT: \(n_{HCl}=2n_{Mg}+2n_{MgO}=0,5\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,5.36,5}{3,65\%}==500\left(g\right)\)
\(Na_2SO_3+2HCl->2NaCl+SO_2+H_2O\\ n_{Na_2SO_3}=0,1mol\\ n_{HCl}=0,3mol\\ \Rightarrow HCl:dư\\ C_{M\left(HCl\right)}=\dfrac{0,1}{0,2}=0,5M\\ C_{M\left(NaCl\right)}=\dfrac{0,2}{0,2}=1M\)
$a\big)$
$n_{CH_3COOH}=\dfrac{100}{1000}.1=0,1(mol)$
$CH_3COOH+NaOH\to CH_3COONa+H_2O$
Theo PT: $n_{NaOH}=n_{CH_3COOH}=0,1(mol)$
$\to C\%_{NaOH}=\dfrac{0,1.40}{50}.100\%=80\%$
$b\big)$
$n_{Na_2CO_3}=\dfrac{10,6}{106}=0,1(mol)$
$2CH_3COOH+Na_2CO_3\to 2CH_3COONa+CO_2+H_2O$
Theo PT: $\begin{cases} n_{CO_2}=n_{Na_2CO_3}=0,1(mol)\\ n_{CH_3COONa}=2n_{Na_2CO_3}=0,2(mol) \end{cases}$
$\to C\%_{CH_3COONa}=\dfrac{0,2.82}{60+10,6-0,1.44}.100\%\approx 24,77\%$
nNaOH = 0,1.2 = 0,2 (mol)
PTHH: CH3COOH + NaOH --> CH3COONa + H2O
0,2<--------0,2
=> \(C_{M\left(dd.CH_3COOH\right)}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\)
nNaOH = 0,1 . 2 = 0,2 (mol)
PTHH: CH3COOH + NaOH -> CH3COONa + H2O
nCH3COOH = nNaOH = 0,2 (mol)
CM(CH3COOH) = 0,2/0,15 = 1,33M
nH2=13,14:22,4=0,6 mol
PTHH: 2Al+6HCl=>2Al2Cl3+3H2
0,4<-1,2<----0,4<-----0,6
=> Al=0,4.27=10,8g
CMHCL=1,2:0,4=3M
CM Al2Cl3=0,4:0,4=1M
bài 2: nH2=0,2mol
PTHH: 2A+xH2SO4=> A2(SO4)x+xH2
0,4:x<---------------------------0,2
ta có PT: \(\frac{13}{A}=\frac{0,4}{x}\)<=> 13x=0,4A
=> A=32,5x
ta lập bảng xét
x=1=> A=32,5 loiaj
x=2=> A=65 nhận
x=3=> A=97,5 loại
=> A là kẽm (Zn)
\(a)n_{MnO_2}=\dfrac{69,6}{87}=0,8mol\\ MnO_2+4HCl\xrightarrow[nhẹ]{đun}MnCl_2+Cl_2+H_2O\)
0,8 3,2 0,8 0,8 0,8
\(V_A=V_{Cl_2}=0,8.22,4=17,92l\\ b)Cl_2+2NaOH\rightarrow NaCl+NaClO+H_2O\)
0,8 1,6 0,8 0,8
\(V_{ddNaOH}=\dfrac{1,6}{1}=1,6l\\ C_{M_{NaCl}}=\dfrac{0,8}{1,6}=0,5M\\ C_{M_{NaClO}}=\dfrac{0,8}{1,6}=0,5M\)
D. 4M
\(Na_2O + 2HCl \rightarrow 2NaCl + H_2O\)
Theo PTHH:
\(n_{HCl}= 2n_{Na_2O}= 2 . 0,2 = 0,4 mol\)
\(\Rightarrow C_M= \dfrac{n_{HCl}}{V_{HCl}}= \dfrac{0,4}{0,1}= 4M\)