cho 4,8 gram Mg tác dụng với dung dịch HCl (dư)
a, viết PTHH
b, tính vH2 thu dược ở đktc
c để có được khí hidro như ở trên thì cần bao nhiêu gram Zn tác dụng với H2SO4
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a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Zn}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)
c, \(n_{HCl}=2n_{Zn}=0,2\left(mol\right)\Rightarrow m_{HCl}=0,2.36,5=7,3\left(g\right)\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(1mol\) \(2mol\) \(1mol\)
\(0,1mol\) \(0,2mol\) \(0,1mol\)
\(n_{Zn}=\dfrac{m}{M}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
\(m_{HCl}=n.M=0,2.36,5=7,3\left(g\right)\)
\(V_{H_2}=n.22,4=0,1.22,4=2,24\left(l\right)\)
\(n_{Zn}=\dfrac{19.5}{65}=0.3\left(mol\right)\)
\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
\(0.3........................0.3..........0.3\)
\(m_{ZnSO_4}=0.3\cdot161=48.3\left(g\right)\)
\(V_{H_2}=0.3\cdot22.4=6.72\left(l\right)\)
\(n_{CuO}=\dfrac{16}{80}=0.2\left(mol\right)\)
\(CuO+H_2\underrightarrow{^{^{t^0}}}Cu+H_2O\)
\(0.2..........0.3\)
\(LTL:\dfrac{0.2}{1}< \dfrac{0.3}{1}\Rightarrow H_2dư\)
\(m_{H_2\left(dư\right)}=\left(0.3-0.2\right)\cdot2=0.2\left(g\right)\)
a) $Zn + H_2SO_4 → ZnSO_4 + H_2$
b) n ZnSO4 = n Zn = 19,5/65 = 0,3(mol)
=> m ZnSO4 = 0,3.161 = 48,3(gam)
c) n H2 = n Zn = 0,3(mol)
V H2 = 0,3.22,4 = 6,72 lít
c)
$CuO + H_2 \xrightarrow{t^o} Cu + H_2O$
n CuO = 16/80 = 0,2(mol) < n H2 = 0,3 nên H2 dư
n H2 pư = n CuO = 0,2(mol)
=> m H2 dư = (0,3 - 0,2).2 = 0,2(gam)
a) PTHH: \(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)
b) Ta có: \(n_{HCl\left(p/ứ\right)}=2n_{Mg}=2\cdot\dfrac{7,2}{24}=0,6\left(mol\right)\)
\(\Rightarrow n_{HCl}=0,6\cdot110\%=0,66\left(mol\right)\) \(\Rightarrow m_{ddHCl}=\dfrac{0,66\cdot36,5}{7,3\%}=330\left(g\right)\)
c) PTHH: \(Fe_2O_3+3H_2\xrightarrow[]{t^o}2Fe+3H_2O\)
Theo PTHH: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=\dfrac{2}{3}n_{Mg}=0,2\left(mol\right)\) \(\Rightarrow m_{Fe}=0,2\cdot56=11,2\left(g\right)\)
nZn = 6,5 : 65 = 0,1 (mol)
pthh: Zn+2HCl -> ZnCl2 + H2
0,1 0,1 0,1
=> mHCl = 0,1 . 36,5 = 3,65(g)
pthh : CuO + H2 -to-> Cu + H2O
0,1 0,1
=> mCu = 0,1 . 64 = 6,4 (g)
1:
a) \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
PTHH: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\)
______0,2------>0,2------------------->0,2_____(mol)
=> \(V_{H_2}=0,2.22,4=4,48\left(l\right)\)
b) \(V_{ddH_2SO_4}=\dfrac{0,2}{1}=0,2\left(l\right)\)
2:
a)
\(n_{HCl}=2.0,2=0,4\left(mol\right)\)
PTHH: \(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)
______0,2<------0,4------------------>0,2______(mol)
=> \(m_{Mg}=0,2.24=4,8\left(g\right)\)
b) \(V_{H_2}=0,2.22,4=4,48\left(l\right)\)
a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Zn}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)
c, PT: \(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)
Theo PT: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=\dfrac{1}{15}\left(mol\right)\Rightarrow m_{Fe}=\dfrac{1}{15}.56=\dfrac{56}{15}\left(g\right)\)
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
a. \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
Theo PTHH: \(n_{ZnSO_4}=n_{Zn}=0,1\left(mol\right)\)
\(\Rightarrow m_{muối}=0,1.161=16,1\left(g\right)\)
b. \(n_{H_2thu.được}=n_{Zn}=0,1\left(mol\right)\)
\(H_2+\dfrac{1}{2}O_2\underrightarrow{t^o}H_2O\)
0,1 0,05
\(V_{O_2}=0,05.22,4=1,12\left(l\right)\)
\(\Rightarrow V_{không.khí}=1,12.5=5,6\left(l\right)\)
\(n_{H2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
a) Pt : \(Mg+H_2SO_4\rightarrow MgSO_4+H_2|\)
1 1 1 1
0,05 0,05
b) \(n_{Mg}=\dfrac{0,05.1}{1}=0,05\left(mol\right)\)
⇒ \(m_{Mg}=0,05.24=1,2\left(g\right)\)
Chúc bạn học tốt
a) nMg=0,2(mol)
PTHH: Mg +2 HCl -> MgCl2 + H2
0,2________0,4____0,2_____0,2(mol)
b) V(H2,đktc)=0,2.22,4=4,48(l)
c) Zn + H2SO4 -> ZnSO4 + H2
0,2<------------------------------0,2(mol)
=>mZn=0,2.65=13(g)
\(n_{Mg}=\dfrac{4.8}{24}=0.2\left(mol\right)\)
\(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(0.2.................................0.2\)
\(V_{H_2}=0.2\cdot22.4=4.48\left(l\right)\)
\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
\(0.2......................................0.2\)
\(m_{Zn}=0.2\cdot65=13\left(g\right)\)