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\(BTNT\left(S\right):n_{SO3}=n_{SO2}=\dfrac{V}{22,4}=\dfrac{5}{14}\left(mol\right)\)
Ta có : \(n_{H2SO4}=\dfrac{9}{25}\left(mol\right)\)
\(\Rightarrow\Sigma n_{H2SO4}=\dfrac{5}{14}+\dfrac{9}{25}=\dfrac{251}{350}\left(mol\right)\)
\(\Rightarrow C\%=\dfrac{m_{H2SO4}}{m_{dd}}.100\%=64,7\%\)
1 , \(n_{Na}=\frac{4,6}{23}=0,2\left(mol\right)\)
\(m_{HCl}=200.2,92\%=5,84\left(mol\right)\) => \(n_{HCl}=\frac{5,84}{36,5}=0,16\left(mol\right)\)
\(2Na+2HCl->2NaCl+H_2\left(1\right)\)
vì \(\frac{0,2}{2}>\frac{0,16}{2}\) => Na dư , HCl hết
dung dịch thu được là dung dịch NaCl
theo (1) \(n_{NaCl}=n_{HCl}=0,16\left(mol\right)\) => \(m_{NaCl}=0,16.58,5=9,36\left(g\right)\)
\(n_{H_2}=\frac{1}{2}n_{HCl}=0,08\left(mol\right)\)
khối lượng dung dịch sau phản ứng là
4,6+200-0,08.2=204,44(g)
\(C_{\%\left(NaCl\right)}=\frac{9,36}{204,44}.100\%\approx4,58\%\)
2SO2+O2<----phản ứng hai chiều,(t0,xt)----> 2SO3
0,037---------------------------------------------->0,375(mol)
nSO2=8/22,4=0,357mol
=> mSO3=0,357.80=28,56gam
\(SO_3+H_2O-->H_2SO_4\)
0,375------------------>0,375mol
=> mH2SO4 mới sinh ra=0,357.98=34,986gam
mdd H2SO4 ban đầu=57,2.1,5=85,8gam
\(=>m_{H2SO4}=\dfrac{85,8}{100}.60=51,48g\)
\(\sum m_{H2SO4}=34,986+51,48=86,466gam\)
\(C\%=\dfrac{86,466}{28,56+85,8}.100\%=75,6\%\).
P/s:Các số liệu trên chỉ lấy với kết quả gần đúng.
PTHH: 2SO2 + O2 --> 2SO3 (1)
SO3 + H2O --> H2SO4 (2)
Theo PT(1): \(n_{SO_2}=n_{SO_3}=\dfrac{8}{22,4}=\dfrac{5}{14}mol\)
=> \(m_{SO_3}=\dfrac{5}{14}.80=\dfrac{200}{7}g\)
Theo PT(2): \(n_{H_2SO_4}=n_{SO_3}=\dfrac{5}{14}mol\)
=> \(m_{H_2SO_4}=\dfrac{5}{14}.98=35g\)
Mặt khác: \(m_{dd.H_2SO_4}\) ban đầu = 57,2.1,5 = 85,8g
=> \(m_{H_2SO_4}\) ( chất tan) = 85,8.60% = 51,48g
=> Tổng khối lượng H2SO4 ( chất tan) = 35 + 51,48 = 86,48g
=> mdd sau p/ứ = \(85,8+\dfrac{200}{7}=\dfrac{4003}{35}g\)
=> C% của dd axit thu được = \(\dfrac{86,48}{\dfrac{4003}{35}}.100\%=75,61\%\)
Ta có: \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
a. PTHH: \(Zn+H_2SO_4--->ZnSO_4+H_2\uparrow\left(1\right)\)
b. Theo PT(1): \(n_{Zn}=n_{H_2}=0,3\left(mol\right)\)
\(\Rightarrow m_{Zn}=65.0,3=19,5\left(g\right)\)
c. Theo PT(1): \(n_{H_2SO_4}=n_{Zn}=0,3\left(mol\right)\)
Đổi 300ml = 0,3 lít
\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,3}{0,3}=1M\)
d. PTHH: \(2NaOH+H_2SO_4--->Na_2SO_4+2H_2O\left(2\right)\)
Theo PT(2): \(n_{NaOH}=2.n_{H_2SO_4}=2.0,3=0,6\left(mol\right)\)
\(\Rightarrow m_{NaOH}=0,6.40=24\left(g\right)\)
\(\Rightarrow m_{dd_{NaOH}}=\dfrac{24.100\%}{20\%}=120\left(g\right)\)
a) Đặt: nMg=x(mol); nZnO=y(mol)
nH2SO4= 0,2(mol)
PTHH: Mg + H2SO4 -> MgSO4 + H2
x___________x____x_______x(mol)
ZnO + H2SO4 -> ZnSO4 + H2O
y____y______y(mol)
Ta có:
\(\left\{{}\begin{matrix}24x+81y=12,9\\22,4x=4,48\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,1\end{matrix}\right.\)
mMg=0,2.24=4,8(g)
%mMg=(4,8/12,9).100=37,209%
=>%mZnO=62,791%
b) nH2SO4=x+y=0,3(mol)
=> \(C\%ddH2SO4=\dfrac{0,3.98}{120}.100=24,5\%\)
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right);n_{SO_2}=\dfrac{10,08}{22,4}=0,45\left(mol\right)\)
PTHH:
Fe + 2HCl ---> FeCl2 + H2
0,2------------------------>0,2
\(2Fe+6H_2SO_{4\left(đ\right)}\xrightarrow[]{t^o}Fe_2\left(SO_4\right)_3+3SO_2+6H_2O\)
0,2---------------------------------------->0,3
\(Cu+2H_2SO_{4\left(đ\right)}\xrightarrow[]{t^o}CuSO_4+SO_2+2H_2O\)
0,15<--------------------------------0,15
=> \(\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{0,2.56}{0,2.56+0,15.64}.100\%=53,85\%\\\%m_{Cu}=100\%-53,85\%=46,15\%\end{matrix}\right.\)
a, \(Cu+2H_2SO_{4\left(đ\right)}\underrightarrow{t^o}CuSO_4+SO_2+2H_2O\)
b, \(n_{SO_2}=\dfrac{3,7185}{24,79}=0,15\left(mol\right)\)
Theo PT: \(n_{Cu}=n_{CuSO_4}=n_{SO_2}=0,15\left(mol\right)\)
\(\Rightarrow m_{Cu}=0,15.64=9,6\left(g\right)=m\)
Theo PT: \(n_{H_2SO_4}=2n_{SO_2}=0,3\left(mol\right)\Rightarrow C\%_{H_2SO_4}=\dfrac{0,3.98}{200}.100\%=14,7\%=x\)
Ta có: m dd sau pư = 9,6 + 200 - 0,15.64 = 200 (g)
\(\Rightarrow C\%_{CuSO_4}=\dfrac{0,15.160}{200}.100\%=12\%\)
Gọi CT oxit KL là \(M_2O_3\)
\(M_2O_3+3H_2SO_4\rightarrow M_2\left(SO_4\right)_3+3H_2O\)
\(n_{M_2O_3}=n_{M_2SO_4}\)
\(\Rightarrow\dfrac{20,4}{2M+48}=\dfrac{68,4}{2M+288}\)
\(\Leftrightarrow M=27\left(Al\right)\)
\(\Rightarrow CT\) \(oxit:Al_2O_3\)
Ta có: \(n_{H_2SO_4}=3n_{Al_2O_3}=3.\dfrac{1}{5}=0,6\left(mol\right)\)
\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,6}{0,3}=2\left(M\right)\)
2SO2 + O2 \(\underrightarrow{to}\) 2SO3 (1)
SO3 + H2O → H2SO4 (2)
\(n_{SO_2}=\dfrac{8}{22,4}=\dfrac{5}{14}\left(mol\right)\)
\(m_{ddH_2SO_4.60\%}=52,7\times1,5=79,05\left(g\right)\)
\(\Rightarrow m_{H_2SO_4.60\%}=79,05\times60\%=47,43\left(g\right)\)
Theo PT1: \(n_{SO_3}=n_{SO_2}=\dfrac{5}{14}\left(mol\right)\)
\(\Rightarrow m_{SO_3}=\dfrac{5}{14}\times80=\dfrac{200}{7}\left(g\right)\)
Theo PT2: \(n_{H_2SO_4}tt=n_{SO_3}=\dfrac{5}{14}\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4}tt=\dfrac{5}{14}\times98=35\left(g\right)\)
\(m_{H_2SO_4}mới=35+47,43=82,43\left(g\right)\)
\(m_{ddH_2SO_4}mới=\dfrac{200}{7}+79,05\approx107,62\left(g\right)\)
\(\Rightarrow C\%_{ddH_2SO_4}mới=\dfrac{82,43}{107,62}\times100\%\approx76,59\%\)