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a) $2Na + 2H_2O \to 2NaOH + H_2$
b) $n_{Na} = \dfrac{2,3}{23} = 0,1(mol)$
Theo PTHH :
$n_{H_2} = \dfrac{1}{2}n_{Na} = 0,05(mol)$
$V_{H_2} = 0,05.22,4 = 1,12(lít)$
c) $n_{CuO} = \dfrac{2,4}{80} = 0,03(mol)$
$CuO + H_2 \xrightarrow{t^o} Cu + H_2O$
Ta thấy :
$n_{CuO} : 1 < n_{H_2} : 1$ nên $H_2$ dư
$n_{Cu} = n_{CuO} = 0,03(mol)$
$m_{Cu} = 0,03.64 = 1,92(gam)$
a, \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
____0,1_____0,2______0,1_____0,1 (mol)
\(V_{H_2}=0,1.24,79=2,479\left(l\right)\)
\(m_{ZnCl_2}=0,1.136=13,6\left(g\right)\)
b, \(C_{M_{HCl}}=\dfrac{0,2}{0,1}=1\left(M\right)\)
c, \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
PT: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)
Xét tỉ lệ: \(\dfrac{0,15}{1}>\dfrac{0,1}{1}\), ta được CuO dư.
Theo PT: \(n_{CuO\left(pư\right)}=n_{Cu}=n_{H_2}=0,1\left(mol\right)\Rightarrow n_{CuO\left(dư\right)}=0,05\left(mol\right)\)
⇒ m chất rắn = mCuO (dư) + mCu = 0,05.80 + 0,1.64 = 10,4 (g)
PTHH: \(SO_2+2NaOH\rightarrow Na_2SO_3+H_2O\)
Ta có: \(n_{NaOH}=0,4\cdot2=0,8\left(mol\right)\)
\(\Rightarrow n_{SO_2}=0,4\left(mol\right)=n_{Na_2SO_3}\) \(\Rightarrow\left\{{}\begin{matrix}V_{SO_2}=0,4\cdot22,4=8,96\left(l\right)\\m_{Na_2SO_3}=0,4\cdot126=50,4\left(g\right)\\C_{M_{Na_2SO_3}}=\dfrac{0,4}{0,4}=1\left(M\right)\end{matrix}\right.\)
a) Fe + H2SO4 --> FeSO4 + H2
b) \(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
PTHH: Fe + H2SO4 --> FeSO4 + H2
0,1------------------------>0,1
=> VH2 = 0,1.22,4 = 2,24 (l)
c) \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
PTHH: CuO + H2 --to--> Cu + H2O
Xét tỉ lệ: \(\dfrac{0,15}{1}>\dfrac{0,1}{1}\) => CuO dư, H2 hết
PTHH: CuO + H2 --to--> Cu + H2O
0,1<--0,1------->0,1
=> mCuO(dư) = (0,15 - 0,1).80 = 4 (g)
mCu = 0,1.64 = 6,4 (g)
a, PT: \(Fe+H_2SO_4\rightarrow H_2SO_4+H_2\)
b, Ta có: \(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Fe}=0,1\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)
c, Ta có: \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
PT: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)
Xét tỉ lệ: \(\dfrac{0,15}{1}>\dfrac{0,1}{1}\), ta được CuO dư.
Theo PT: \(n_{Cu}=n_{CuO\left(pư\right)}=n_{H_2}=0,1\left(mol\right)\)
\(\Rightarrow n_{CuO\left(dư\right)}=0,05\left(mol\right)\Rightarrow m_{CuO\left(dư\right)}=0,05.80=4\left(g\right)\)
\(m_{Cu}=0,1.64=6,4\left(g\right)\)
Bạn tham khảo nhé!
Bài 1.
\(n_{Fe}=\dfrac{5,6}{56}=0,1mol\)
\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
0,1 0,1 0,1 0,1
\(V_{H_2}=0,1\cdot22,4=2,24l\)
\(n_{CuO}=\dfrac{12}{80}=0,15mol\)
\(CuO+H_2\rightarrow Cu+H_2O\)
0,15 0,1
\(\Rightarrow CuO\) dư và dư \(\left(0,15-0,1\right)\cdot80=4g\)
Bài 2.
\(n_P=\dfrac{3,1}{31}=0,1mol\)
\(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
0,1 0,125
\(V_{O_2}=0,125\cdot22,4=2,8l\)
\(n_{Zn}=\dfrac{19,5}{65}=0,3mol\)
\(2Zn+O_2\underrightarrow{t^o}2ZnO\)
0,3 0,125 0
0,25 0,125 0,25
0,05 0 0,25
\(\Rightarrow ZnO\) dư và dư \(0,05\cdot81=4,05g\)
Bài 1.
a, \(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
PTHH: Fe + H2SO4 ---> FeSO4 + H2
Mol: 0,1 0,1
b, \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)
c, \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
Ta có: \(\dfrac{0,15}{1}>\dfrac{0,1}{1}\) ⇒ CuO dư, H2 hết
PTHH: CuO + H2 ---to----> Cu + H2O
Mol: 0,1 0,1
\(m_{CuOdư}=\left(0,15-0,1\right).80=4\left(g\right)\)
a.b.
\(n_{Na}=\dfrac{13,8}{23}=0,6mol\)
\(2Na+2H_2O\rightarrow2NaOH+H_2\)
0,6 0,3 ( mol )
\(V_{H_2}=0,3.22,4=6,72l\)
c.\(n_{CuO}=\dfrac{12}{80}=0,15mol\)
\(CuO+H_2\rightarrow\left(t^o\right)Cu+H_2O\)
0,15 < 0,3 ( mol )
0,15 0,15 ( mol )
Chất dư là H2
\(m_{H_2}=\left(0,3-0,15\right).2=0,3g\)