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n H2SO4= m/M= 19.6/98=0.2
Pt: 2Al + 3H2SO4= Al2(SO4)3 + 3H2
2/15------ 0,2----------------------0,2
a> mAl= n.M= 2/15.27=3.6g
b> VH2= n.22,4=0,2.22,4=4,48(l)
Đặng Khánh Duy ai đùa làm gì? tính m dung dịch sai thì sai cả C% rồi còn đâu
a. nFe= 0,6 (mol)
3Fe+2O2 --t0--> Fe3O4
0,6 0,4 0,6
VO2= 0,4 * 22,4 = 8,96(l)
mFe3O4= 0,6 * 232=139,2(g)
b. C%= \(\dfrac{m_{ct}}{m_{dd}}\)*100%
=> 10% = \(\dfrac{m_{H2SO4}}{196}\)*100% => mH2SO4 = \(\dfrac{1960}{100}\)= 19,6g
a)PTHH
3Fe + 2O2 --to--> Fe3O4
nFe=\(\dfrac{33,6}{56}\) = 0,9 mol
+)nO2=2/3.0,9=0,6 mol
=>VO2=0,6.22,4=13,44(l)
+)nFe3O4=1/3.0,9=0,3 mol
=>mFe3O4=0,3.232=69,6 (g)
b)
mH2SO4=\(\dfrac{C\%ddH2SO4.196}{100\%}=\dfrac{10\%.196}{100\%}=19,6\left(g\right)\)
a) PTHH :\(Fe_2O_3+3H_2SO_4->Fe_2\left(SO_4\right)_3+3H_2O\)
b) Ta có :\(n_{Fe_2O_3}=\dfrac{48}{160}=0,3\left(mol\right);n_{H_2SO_4}=\dfrac{58,8}{98}=0,6\left(mol\right)\)
\(Fe_2O_3+3H_2SO_4->Fe_2\left(SO_4\right)_3+3H_2O\)
1______3
\(\dfrac{1}{0,3}< \dfrac{3}{0,6}\)
=>\(n_{H_2SO_4}dư=>n_{H_2SO_{4\left(dư\right)}}=0,9mol=>m_{H_2SO_4\left(dư\right)}=0,9.98=88,2\left(g\right)\)
=>
CuO + H2SO4 → CuSO4 + H2O (1)
Al2O3 + 3H2SO4 → Al2(SO4)3 + 3H2O (2)
Gọi \(x,y\) lần lượt là số mol của CuO và Al2O3
Theo PT1: \(n_{CuSO_4}=n_{CuO}=x\left(mol\right)\)
TheoPT2: \(n_{Al_2\left(SO_4\right)_3}=n_{Al_2O_3}=y\left(mol\right)\)
Ta có: \(\left\{{}\begin{matrix}160x+342y=57,9\\80x+102y=25,5\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,255\\y=0,05\end{matrix}\right.\)
Vậy \(n_{CuO}=0,255\left(mol\right);n_{Al_2O_3}=0,05\left(mol\right)\)
\(\Rightarrow m_{Al_2O_3}=0,05\times102=5,1\left(g\right)\)
\(\Rightarrow\%Al_2O_3=\dfrac{5,1}{25,5}\times100\%=20\%\)
Bài 1:
\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
\(n_{Al_2O_3}=\dfrac{m}{M}=\dfrac{20,4}{102}=0,2\left(mol\right)\)
Theo PTHH, \(n_{Al}=2n_{Al_2O_3}=2\cdot0,2=0,4\left(mol\right)\)
\(m_{Al}=n\cdot M=0,4\cdot27=10,8\left(g\right)\)
Theo PTHH, \(n_{O_2}=\dfrac{3}{2}n_{Al_2O_3}=\dfrac{3}{2}\cdot0,2=0,3\left(mol\right)\)
\(V_{O_2}=n\cdot22,4=0,3\cdot22,4=6,72\left(l\right)\)
Bài 1:
4Al + 3O2 \(\underrightarrow{to}\) 2Al2O3
\(n_{Al_2O_3}=\dfrac{20,4}{102}=0,2\left(mol\right)\)
a) theo PT: \(n_{Al}=2n_{Al_2O_3}=2\times0,2=0,4\left(mol\right)\)
\(\Rightarrow m=m_{Al}=0,2\times27=5,4\left(g\right)\)
b) theo PT: \(n_{O_2}=\dfrac{3}{2}n_{Al_2O_3}=\dfrac{3}{2}\times0,2=0,3\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,3\times22,4=6,72\left(l\right)\)
Bài 1:
3NaOH + FeCl3 → 3NaCl + Fe(OH)3↓
\(n_{NaOH}=\frac{20}{40}=0,5\left(mol\right)\)
a) Theo PT: \(n_{FeCl_3}=\frac{1}{3}n_{NaOH}=\frac{1}{3}\times0,5=\frac{1}{6}\left(mol\right)\)
\(\Rightarrow m_{FeCl_3}=\frac{1}{6}\times162,5=27,083\left(g\right)\)
b) Theo pT: \(n_{NaCl}=n_{NaOH}=0,5\left(mol\right)\)
\(\Rightarrow m_{NaCl}=0,5\times58,5=29,25\left(g\right)\)
Theo pT: \(n_{Fe\left(OH\right)_3}=n_{FeCl_3}=\frac{1}{6}\left(mol\right)\)
\(\Rightarrow m_{Fe\left(OH\right)_3}=\frac{1}{6}\times107=17,83\left(g\right)\)
Bài 2:
CaCO3 \(\underrightarrow{to}\) CaO + H2O
a) \(n_{CaO}=\frac{11,2}{56}=0,2\left(mol\right)\)
Theo PT: \(n_{CaCO_3}=n_{CaO}=0,2\left(mol\right)\)
\(\Rightarrow m_{CaCO_3}=0,2\times100=20\left(g\right)\)
b) \(n_{CaO}=\frac{35}{56}=0,625\left(mol\right)\)
Theo PT: \(n_{CaCO_3}=n_{CaO}=0,625\left(mol\right)\)
\(\Rightarrow m_{CaCO_3}=0,625\times100=62,5\left(g\right)\)
c) Theo pT: \(n_{CO_2}=n_{CaCO_3}=0,5\left(mol\right)\)
\(\Rightarrow V_{CO_2}=0,5\times22,4=11,2\left(l\right)\)
d) \(n_{CO_2}=\frac{33,6}{22,4}=1,5\left(mol\right)\)
Theo pT: \(n_{CaCO_3}=n_{CO_2}=1,5\left(mol\right)\)
\(\Rightarrow m_{CaCO_3}=1,5\times100=150\left(g\right)\)
Theo pT: \(n_{CaO}=n_{CO_2}=1,5\left(mol\right)\)
\(\Rightarrow m_{CaO}=1,5\times56=84\left(g\right)\)
a) 2Al+ 3H2SO4-> Al2(SO4)3+3H2
b) 2Fe(OH)3+ 3H2SO4-> Fe2(SO4)3+ 6H2O
a) 2Al + 3H2SO4 \(\rightarrow\) Al2(SO4)3 + 3H2
b) 2Fe(OH)3 + 3H2SO4 \(\rightarrow\) Fe2(SO4)3 + 6H2O
a. 4P + 5O2 \(\underrightarrow{t^o}\) 2P2O5
b. 4Al + 3O2 \(\underrightarrow{t^o}\) 2Al2O3
c. Fe + 2HCl \(\rightarrow\) FeCl2 + H2\(\uparrow\)
d. H2 + CuO \(\underrightarrow{t^o}\) Cu + H2O
e. 3CO + Fe2O3 \(\underrightarrow{t^o}\) 2Fe + 3CO2\(\uparrow\)
f. Cu + 2H2SO4 \(\rightarrow\) CuSO4 + SO2\(\uparrow\) + 2H2O
g. Fe + 4HNO3 \(\rightarrow\) Fe(NO3)3 + NO\(\uparrow\) + 2H2O
h. 2Al + 3H2SO4 \(\rightarrow\) Al2(SO4)3 + 3H2\(\uparrow\)
i. Ca(HCO3)2 \(\underrightarrow{t^o}\) CaCO3 + CO2\(\uparrow\) + H2O
2Al + 3H2SO4 → Al2(SO4)3 + 3H2
\(n_{Al}=\dfrac{27}{27}=1\left(mol\right)\)
Theo PT: \(n_{H_2SO_4}=\dfrac{3}{2}n_{Al}=\dfrac{3}{2}\times1=1,5\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4}=1,5\times98=147\left(g\right)\)