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\(n_{Zn}=\dfrac{13}{65}=0,2mol\)
\(n_{H_2SO_4}=0,04.1=0,04mol\)
\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
0,2 > 0,04 ( mol )
0,04 0,04 0,04 0,04 ( mol )
\(m_{ZnSO_4}=0,04.161=6,44g\)
Câu b ko hiểu lắm bạn ơi!
a)
$n_{Zn} = \dfrac{13}{65} = 0,2(mol) ; n_{H_2 SO_4} = 0,5.2 = 1(mol)$
$Zn + H_2SO_4 \to ZnSO_4 + H_2$
Ta thấy :
$n_{Zn} < n_{H_2SO_4}$ nên $H_2SO_4$ dư
$n_{ZnSO_4} = n_{H_2SO_4\ pư} = n_{Zn} = 0,2(mol)$
$m_{ZnSO_4} = 0,2.161=32,2(gam)$
$m_{H_2SO_4\ pư} = 0,2.98 = 19,6(gam)$
b)
$n_{H_2SO_4\ dư} = 1 - 0,2 = 0,8(mol)$
$C_{M_{H_2SO_4\ dư}} = \dfrac{0,8}{0,5} = 1,6M$
$C_{M_{FeSO_4}} = \dfrac{0,2}{0,5} = 0,4M$
\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\\ n_{H_2SO_4}=0,5.2=1\left(mol\right)\\ Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\ a.Vì:\dfrac{0,2}{1}< \dfrac{1}{1}\Rightarrow H_2SO_4dư\\ n_{H_2SO_4\left(p.ứ\right)}=n_{ZnSO_4}=n_{Zn}=0,2\left(mol\right)\\ m_{H_2SO_4\left(p.ứ\right)}=0,2.98=19,6\left(g\right)\\ m_{ZnSO_4}=161.0,2=32,2\left(g\right)\\ b.V_{ddsau}=V_{ddH_2SO_4}=0,5\left(l\right)\\ C_{MddZnSO_4}=\dfrac{0,2}{0,5}=0,4\left(M\right)\\ C_{MddH_2SO_4\left(dư\right)}=\dfrac{1-0,2}{0,5}=1,6\left(M\right)\)
\(n_{Na}=\dfrac{4,6}{23}=0,2mol\)
\(2Na+2H_2O\rightarrow2NaOH+H_2\)
0,2 0,2 0,2 0,1
\(V_{H_2}=0,1\cdot22,4=2,24l\)
\(m_{NaOH}=0,2\cdot40=8g\)
\(m_{ddNaOH}=4,6+0,2\cdot18-0,1\cdot2=8g\)
\(\Rightarrow C\%=\dfrac{m_{NaOH}}{m_{ddNaOH}}\cdot100\%=\dfrac{8}{8}\cdot100\%=100\%???\)
Sửa đề: Tính nồng độ mol của dung dịch NaOH???
\(C_{M_{NaOH}}=\dfrac{0,2}{0,3}=\dfrac{2}{3}M\)
a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Ta có: \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
Theo PT: \(n_{ZnCl_2}=n_{H_2}=n_{Zn}=0,2\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,2.24,79=4,958\left(l\right)\)
b, \(n_{HCl}=2n_{Zn}=0,4\left(mol\right)\Rightarrow V_{HCl}=\dfrac{0,4}{2}=0,2\left(l\right)\)
c, \(C_{M_{ZnCl_2}}=\dfrac{0,2}{0,2}=1\left(M\right)\)
$a\big)2Al+3H_2SO_4\to Al_2(SO_4)_3+3H_2$
$b\big)$
$n_{Al}=\dfrac{2,7}{27}=0,1(mol)$
Theo PT: $n_{H_2SO_4}=1,5n_{Al}=0,15(mol)$
$\to m_{dd\,H_2SO_4}=\dfrac{0,15.98}{30\%}=49(g)$
$c\big)$
Theo PT: $n_{H_2}=0,15(mol);n_{Al_2(SO_4)_3}=0,05(mol)$
$\to V_{H_2}=0,15.22,4=3,36(l)$
$\to m_{Al_2(SO_4)_3}=0,05.342=17,1(g)$
a, PT: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)
b, Ta có: \(n_{H_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)
Theo PT: \(n_{Zn}=n_{H_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{Zn}=0,5.65=32,5\left(g\right)\)
\(\Rightarrow m_{CuO}=72,5-32,5=40\left(g\right)\)
c, Ta có: \(n_{CuO}=\dfrac{40}{80}=0,5\left(mol\right)\)
Theo PT: \(n_{H_2SO_4}=n_{Zn}+n_{CuO}=1\left(mol\right)\)
\(\Rightarrow b=C_{M_{H_2SO_4}}=\dfrac{1}{2,5}=0,4M\)
c, Theo PT: \(\left\{{}\begin{matrix}n_{ZnSO_4}=n_{Zn}=0,5\left(mol\right)\\n_{CuSO_4}=n_{CuO}=0,5\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}C_{M_{ZnSO_4}}=\dfrac{0,5}{2,5}=0,2M\\C_{M_{CuSO_4}}=\dfrac{0,5}{2,5}=0,2M\end{matrix}\right.\)
Bạn tham khảo nhé!
a, \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\left(I\right)\)
\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\left(II\right)\)
b, Theo PTHH(1) : \(n_{Zn}=n_{H_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{Zn}=32,5\left(g\right)\)
\(\Rightarrow m_{CuO}=m_{hh}-m_{Zn}=40\left(g\right)\)
\(\Rightarrow n_{CuO}=\dfrac{m}{M}=0,5\left(mol\right)\)
c, Theo PTHH (1) và (2) : \(n_{H2SO4}=n_{CuO}+n_{Zn}=1\left(mol\right)\)
\(\Rightarrow C_{MH2SO4}=b=\dfrac{n}{V}=\dfrac{1}{2,5}=0,4M\)
d, ( Chắc là thể tích coi như không đổi )
Thấy sau phản ứng thu được A gồm \(0,5molZnSO_4,0,5molCuSO_4\)
\(\Rightarrow C_{MCuSO4}=C_{MZnSO4}=\dfrac{n}{V}=\dfrac{0,5}{2,5}=0,2M\)
Vậy ...
a) \(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)
PTHH: 2Al + 3H2SO4 --> Al2(SO4)3 + 3H2
0,4-->0,6---------->0,2------->0,6
=> \(C_{M\left(dd.H_2SO_4\right)}=\dfrac{0,6}{0,15}=4M\)
b) VH2 = 0,6.22,4 = 13,44 (l)
c) \(C_{M\left(Al_2\left(SO_4\right)_3\right)}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\)
\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\\
pthh:2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
0,4 0,6 0,2 0,6
\(C_M_{H_2SO_4}=\dfrac{0,6}{0,15}=4M\\ V_{H_2}=0,622,4=13,44L\)
\(C_M=\dfrac{0,2}{0,15}=1,3M\)
a, \(H_2SO_4+Zn=ZnSO_4+H_2\uparrow\)
b,
\(n_{Zn}=\frac{13}{65}=0,2\left(mol\right)\)
Theo PTHH : \(n_{Zn}=n_{H_2}=0,2\left(mol\right)\)
\(\Rightarrow V_{H_2=}=n_{H_2}\cdot22,4=0,2\cdot22,4=4,48\left(l\right)\)
bn chx lm hết à