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\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\)
PTHH: Fe + 2HCl --> FeCl2 + H2
0,2------------>0,2----->0,2
=> \(\left\{{}\begin{matrix}m_{FeCl_2}=0,2.127=25,4\left(g\right)\\V_{H_2}=0,2.22,4=4,48\left(l\right)\end{matrix}\right.\)
$m_{HCl}=20\%.54,75=10,95g$
$⇒n_{HCl}=\dfrac{10,95}{36,5}=0,3mol$
$PTHH :$
$2Al+6HCl\to 2AlCl_3+3H_2$
$Theo$ $pt :$
$n_{Al}=\dfrac{1}{3}.n_{HCl}=\dfrac{1}{3}.0,3=0,1mol$
$⇒m_{Al}=0,1.27=2,7g$
$n_{H_2}=n_{HCl}=0,3mol$
$⇒V_{H_2}=0,3.22,4=6,72l$
Bài 3:
$n_{Fe}=\dfrac{11,2}{56}=0,2(mol)$
$Fe+2HCl\to FeCl_2+H_2\uparrow$
Theo PT: $n_{FeCl_2}=n_{H_2}=0,2(mol)$
$\Rightarrow m_{FeCl_2}=0,2.127=25,4(g);V_{H_2}=0,2.22,4=4,48(lít)$
$\Rightarrow m=25,4;V=4,48$
Bài 4:
$CuO+H_2SO_4\to CuSO_4+H_2O$
Theo PT; $n_{H_2SO_4}=n_{CuSO_4}=n_{CuO}=\dfrac{32}{80}=0,4(mol)$
$\Rightarrow m_{H_2SO_4}=0,4.98=39,2(g)$
$m_{CuSO_4}=0,4.160=64(g)$
a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
b, Ta có: \(n_{HCl}=0,5.0,2=0,1\left(mol\right)\)
\(n_{H_2}=\dfrac{0,896}{22,4}=0,04\left(mol\right)\)
Theo PT: \(n_{HCl\left(pư\right)}=2n_{H_2}=0,08\left(mol\right)< 0,1\left(mol\right)\)
→ HCl dư.
Gọi: \(\left\{{}\begin{matrix}n_{Zn}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\)
Theo PT: \(n_{H_2}=n_{Zn}+n_{Fe}=x+y=0,04\left(1\right)\)
\(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=x\left(mol\right)\\n_{FeCl_2}=n_{Fe}=y\left(mol\right)\end{matrix}\right.\)⇒ 136x + 127y = 5,26 (2)
Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}x=0,02\left(mol\right)\\y=0,02\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,02.65}{0,02.65+0,02.56}.100\%\approx53,72\%\\\%m_{Fe}\approx46,28\%\end{matrix}\right.\)
Gọi \(n_{Fe}=x\left(mol\right)\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
\(n_{FeCl_2}=n_{Fe}=x\left(mol\right)\)
Vì khối lượng muối FeCl2 tăng 7,1g so với khối lượng bột Fe
\(\Rightarrow127x-56x=7,1\\ \Rightarrow x=0,1\)
\(n_{H_2}=n_{Fe}=0,1\left(mol\right)\\ V_{H_2\left(ĐKTC\right)}=0,1.22,4=2,24\left(l\right)\)
Chọn D
$n_{Fe}=\dfrac{2,24}{56}=0,04(mol)$
$a,PTHH:Fe+2HCl\to FeCl_2+H_2$
$b,$ Theo PT: $n_{H_2}=n_{Fe}=0,04(mol)$
$\Rightarrow V_{H_2}=0,04.22,4=0,896(l)$
a) nFe= 5,6/56=0,1(mol)
nHCl=10,95/36,5=0,3(mol)
PTHH: Fe + 2 HCl -> FeCl2 + H2
Ta có: 0,3/2 > 0,1/1
=> HCl dư, Fe hết, tính theo nFe
-> nH2=nFeCl2=nFe=0,1(mol)
=> V(H2,đktc)=0,1.22,4=2,24(l)
mFeCl2=0,1.127=12,7(g)
pứ: Fe + 2HCl -> FeCl2 + H2
b. nFe = \(\dfrac{5,6}{56}\)= 0,1 mol
Từ pt suy ra được: nHCl = 2.nFe= 0,2 mol
=> mHCl = 0,2. 36,5 = 7,3 g
c. nH2 = nFe = 0,1 mol
=> VH2 = 0,1.22,4 = 2,24 (lít)
$n_{HCl}=0,2.0,5=0,1mol$
$PTHH :$
$Fe+2HCl\to FeCl_2+H_2$
$Theo\ pt :$
$n_{Fe}=n_{H_2}=\dfrac{1}{2}.n_{HCl}=\dfrac{1}{2}.0,1=0,05mol$
\(\Rightarrow\)$m=m_{Fe}=0,05.56=2,8g$
$V=V_{H_2}=0,05.22,4=1,12l$