Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Câu 7 :
\(n_{H2}=\dfrac{17,92}{22,4}=0,8\left(mol\right)\)
Pt : \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2|\)
2 3 1 3
\(\dfrac{8}{15}\) 0,8 \(\dfrac{4}{15}\) 0,8
\(n_{H2SO4}=\dfrac{0,8.3}{3}=0,8\left(mol\right)\)
⇒ \(m_{H2SO4}=0,8.98=78,4\left(g\right)\)
\(n_{Al2\left(SO4\right)3}=\dfrac{0,8.1}{3}=\dfrac{4}{15}\left(mol\right)\)
⇒ \(m_{Al2\left(SO4\right)3}=\dfrac{4}{15}.342=91,2\left(g\right)\)
\(n_{Al}=\dfrac{0,8.2}{3}=\dfrac{8}{15}\left(mol\right)\)
⇒ \(m_{Al}=\dfrac{8}{15}.27=14,4\left(g\right)\)
Chúc bạn học tốt
Bài 1 :
a) Pt : 2Ba + O2 → (to) 2BaO
b) Pt : 2Fe(OH)3 + 3H2SO4 → Fe2(SO4)3 + 6H2O
c) Pt : ZnCl2 + 2NaOH → Zn(OH)2 + 2NaCl
d) Pt : Na2CO3 + 2HCl → 2NaCl + CO2 + H2O
Chúc bạn học tốt
$a) Fe + 2HCl \to FeCl_2 + H_2$
$b) n_{Fe} = \dfrac{5,6}{56} = 0,1(mol)$
Theo PTHH : $n_{HCl} = 2n_{Fe} = 0,1.2 = 0,2(mol)$
$m_{HCl} = 0,2.36,5 = 7,3(gam)$
$c) n_{H_2} = n_{Fe} = 0,1(mol)$
$V_{H_2} = 0,1.22,4 = 2,24(lít)$
a: \(Fe+2HCl\rightarrow FeCl_2+H_2\)
b: \(n_{Fe}=\dfrac{5.6}{56}=0.1\left(mol\right)=n_{FeCl_2}\)
\(\Leftrightarrow n_{HCl}=2\cdot0.1=0.2\left(mol\right)\)
\(m=0.2\cdot36.5=7.3\left(g\right)\)
c: \(V_{H_2}=0.1\cdot22.4=2.24\left(lít\right)\)
a,\(n_{Mg}=\dfrac{9,6}{24}=0,4\left(mol\right);n_{H_2SO_4}=1,5.0,2=0,3\left(mol\right)\)
PTHH: Mg + H2SO4 → MgSO4 + H2
Mol: 0,3 0,3 0,3
Ta có: \(\dfrac{0,4}{1}>\dfrac{0,3}{1}\) ⇒ Mg dư, H2SO4 pứ hết
\(m_{MgSO_4}=0,3.120=36\left(g\right)\)
b,\(V_{H_2}=0,3.22,4=6,72\left(l\right)\)
c, \(n_{Fe_2O_3}=\dfrac{6,4}{160}=0,04\left(mol\right)\)
PTHH: 3H2 + Fe2O3 → 2Fe + 3H2O
Mol: 0,04 0,08
Ta có: \(\dfrac{0,3}{3}>\dfrac{0,04}{1}\) ⇒ H2 dư, Fe2O3 pứ hết
\(\Rightarrow m_{Fe}=0,08.56=4,48\left(g\right)\)
a. \(Fe+2HCl\rightarrow FeCl_2+H_2\)
b. \(n_{Fe}=\dfrac{m_{Fe}}{M_{Fe}}=\dfrac{28}{56}=0,5\left(mol\right)\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,5-------1---------0,5-----0,5
Theo PTHH: \(\Rightarrow n_{H_2}=n_{Fe}=0,5\left(mol\right)\)
\(V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)
c. \(H_2+CuO\rightarrow Cu+H_2O\)
0,5-------0,5-----0,5----0,5
\(\Rightarrow m_{Cu}=n_{Cu}.M_{Cu}=0,5.64=32\left(g\right)\)
B1 : nFe = 11,2 /56 = 0,2 (mol)
Fe+ 2HCl -- . FeCl2 + H2
mFeCl2 = 0,2.127 = 25,4 (g)
VH2 = 0,2 .22,4 = 4,48 (l)
mHCl = 0,4.36,5 = 14,6(g)
C%\(_{ddHCl}=\dfrac{ }{ }\)\(\dfrac{14,6.100}{280}=5,2\%\)
C2 :
2Al + 3H2SO4 -- > Al2(SO4)3 + 3H2
nH2 = 17,92/22,4 = 0,8 (mol)
mAl = (2/3.0,8 ) .27 = 14,4 (g)
mAl2(SO4)3 = (1/3 . 0,8 ) . 342 = 91,2 (g)
mH2SO4 = 0,8 . 98 = 78,4 (g)
\(C\%_{ddH_2SO_4}=\dfrac{78,4.100}{120}=65,33\%\)
Bài 1:
1) Fe + 2HCl --> FeCl2 + H2
2) \(n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\)
PTHH: Fe + 2HCl --> FeCl2 + H2
_____0,3--------------->0,3--->0,3
=> nH2 = 0,3.22,4 = 6,72(l)
3) mFeCl2 = 0,3.127=38,1(g)
Bài 2
1) 2Al + 3H2SO4 --> Al2(SO4)3 + 3H2
2) \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
PTHH: 2Al + 3H2SO4 --> Al2(SO4)3 + 3H2
______0,2<----------------------------------0,3
=> mAl = 0,2.27 = 5,4(g)