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Câu 6:
1. \(n_{O_2}=\dfrac{2,470}{24,79}=0,1\left(mol\right)\)
PTHH:
\(4Al+3O_2\rightarrow\left(t^o\right)2Al_2O_3\)
2/15 0,1 1/15
\(m_{Al}=\dfrac{2}{15}.27=3,6\left(g\right)\)
2. Gọi m KCl cần thêm là x
Ta có:
\(15\%=\dfrac{\dfrac{10x.10}{100}+\dfrac{300.25}{100}}{10x+300}\)
\(\Rightarrow x=60\)
Vậy \(m_{ddKCl}=\dfrac{60.100}{10}=600\left(g\right)\)
PT: \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
Ta có: \(n_{H_2}=\dfrac{3,7185}{24,79}=0,15\left(mol\right)\)
a, \(n_{Al}=\dfrac{2}{3}n_{H_2}=0,1\left(mol\right)\Rightarrow m_{Al}=0,1.27=2,7\left(g\right)\)
b, \(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{H_2}=0,05\left(mol\right)\)
\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=0,05.342=17,1\left(g\right)\)
c, \(n_{H_2SO_4}=n_{H_2}=0,15\left(mol\right)\)
\(\Rightarrow V_{H_2SO_4}=\dfrac{0,15}{1,5}=0,1\left(l\right)=100\left(ml\right)\)
\(n_{H_2\left(đkc\right)}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\\ 2Al+6HCl\rightarrow2AlCl_3+3H_2\\ n_{Al}=n_{AlCl_3}=\dfrac{2}{3}.n_{H_2}=\dfrac{2}{3}.0,1=\dfrac{1}{15}\left(mol\right)\\ \Rightarrow m_{Al}=27.\dfrac{1}{15}=1,8\left(g\right)\\ m_{AlCl_3}=\dfrac{1}{15}.133,5=8,9\left(g\right)\)
\(n_{H_2}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\)
PTHH: 2Al + 6HCl --> 2AlCl3 + 3H2
\(\dfrac{1}{15}\)<--------------\(\dfrac{1}{15}\)<-----0,1
=> \(m_{Al}=\dfrac{1}{15}.27=1,8\left(g\right)\)
=> \(m_{AlCl_3}=\dfrac{1}{15}.133,5=8,9\left(g\right)\)
2Al + 3H2SO4 -- > Al2(SO4)3 + 3H2
0,3 0,45 0,15 0,45
nAl = 8,1 / 27 = 0,3(mol)
\(VH_2=0,45.22,4=10,08\left(g\right)\)
\(m\left(muối\right)=0,15.342=51,3\left(g\right)\)
\(H_2+CuO\rightarrow Cu+H_2O\)
0,45 0,45
mCu = 0,45 . 64 = 28,8(g)
bạn giải thích dùm mình tại sao 3H2So4 với 3H2 lại là 0,45 mol ko
a) \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
PTHH: 4Al + 3O2 --to--> 2Al2O3
0,2-->0,15
=> V = 0,15.22,4 = 3,36 (l)
b)
PTHH: 2KMnO4 --to--> K2MnO4 + MnO2 + O2
0,3<----------------------------0,15
=> mKMnO4(lý thuyết) = 0,3.158 = 47,4 (g)
=> \(m_{KMnO_4\left(tt\right)}=\dfrac{47,4.110}{100}=52,14\left(g\right)\)
a) Fe + 2HCl --> FeCl2 + H2
b) \(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
PTHH: Fe + 2HCl --> FeCl2 + H2
0,05<-0,1<-----------0,05
=> m = 0,05.56 = 2,8 (g)
c) \(m_{HCl}=0,1.36,5=3,65\left(g\right)\Rightarrow m_{dd.HCl}=\dfrac{3,65.100}{10}=36,5\left(g\right)\)
\(n_{H_2}=\dfrac{3,7185}{24,79}=0,15\left(mol\right)\)
PTHH: 2Al + 6HCl ---> 2AlCl3 + 3H2
0,1<---------------0,1<-----0,15
\(\Rightarrow\left\{{}\begin{matrix}a,m_{Al}=0,1.27=2,7\left(g\right)\\b,m_{AlCl_3}=0,1.133,5=13,35\left(g\right)\end{matrix}\right.\)
1. \(n_{O_2}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\)
\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
Theo PT: \(n_{Al}=\dfrac{4}{3}n_{O_2}=\dfrac{2}{15}\left(mol\right)\Rightarrow m_{Al}=\dfrac{2}{15}.27=3,6\left(g\right)\)
2. \(n_{KCl\left(25\%\right)}=300.25\%=75\left(g\right)\)
Gọi: m dd KCl 10% = a (g) ⇒ mKCl (10%) = 10%a (g)
\(\Rightarrow\dfrac{75+10\%a}{a+300}=0,15\Rightarrow a=600\left(g\right)\)