hòa tan hoàn toàn 6,5g Zn vào 100ml dung dịch HCl
a) tính thể tích khí hiđro thoát ra (đktc)
b) tính nồng độ mol dung dịch HCl đã phản ứng
c) nếu dùng 50ml dung dịch HCl trên trung hòa V ml dung dịch Ca(OH)2 2M tính V?
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câu 1
\(n_{Fe}=\dfrac{14}{56}=0,25\left(mol\right)\\ pthh:Fe+2HCl\rightarrow FeCl_2+H_2\)
0,25 0,5 0,25 0,25
\(m_{FeCl_2}=0,25.127=31,75g\\
V_{H_2}=0,25.22,4=5,6\\
C_{M\left(HCl\right)}=\dfrac{0,5}{0,2}=2,5M\)
câu 2
1 ) \(m_{\text{dd}}=35+100=135g\\
2,C\%=\dfrac{204}{204+100}.100=60\%\\
=>m\text{dd}=\dfrac{100.204}{60}=340g\)
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
\(C_M_{H_2SO_4}=\dfrac{0,6}{0,15}=4M\\ V_{H_2}=0,622,4=13,44L\)
\(C_M=\dfrac{0,2}{0,15}=1,3M\)
\(n_{Zn}=\dfrac{9,75}{65}=0,15mol\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
0,15 0,3 0,15 0,15
\(m_{ZnCl_2}=0,15\cdot136=20,4\left(g\right)\)
\(V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\)
\(C_{M_{HCl}}=\dfrac{0,3}{0,1}=3M\)
a)
\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
PTHH: Zn + 2HCl --> ZnCl2 + H2
0,2-->0,4----->0,2--->0,2
=> VH2 = 0,2.22,4 = 4,48 (l)
b) mHCl = 0,4.36,5 = 14,6 (g)
=> \(m_{dd.HCl}=\dfrac{14,6.100}{7,3}=200\left(g\right)\)
c)
mdd sau pư = 13 + 200 - 0,2.2 = 212,6 (g)
mZnCl2 = 0,2.136 = 27,2 (g)
=> \(C\%=\dfrac{27,2}{212,6}.100\%=12,8\%\)
a) $CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$
Theo PTHH :
$n_{CO_2} = n_{CaCO_3} = \dfrac{10}{100} = 0,1(mol)$
$V_{CO_2} = 0,1.22,4 = 2,24(lít)$
b) $n_{HCl} = 2n_{CaCO_3} = 0,2(mol)$
$C_{M_{HCl}} = \dfrac{0,2}{0,25} = 0,8M$
c) $CO_2 + Ca(OH)_2 \to CaCO_3 + H_2O$
$n_{CaCO_3} = n_{CO_2} = 0,1(mol)$
$m_{CaCO_3} = 0,1.100 = 10(gam)$
a, \(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)
b, \(n_{Mg}=\dfrac{12}{24}=0,5\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Mg}=0,5\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,5.22,4=11,2\left(l\right)\)
c, \(n_{H_2SO_4}=n_{Mg}=0,5\left(mol\right)\)
\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,5}{0,1}=5\left(M\right)\)
1.
\(n_{Mg}=\dfrac{m_{Mg}}{M_{Mg}}=\dfrac{12}{24}0,5mol\)
đổi \(100ml=0,1l\)
PTHH: Mg + H2SO4 \(\rightarrow\) MgSO4 + H2
TL: 1 : 1 : 1 : 1
mol: 0,5 \(\rightarrow\) 0,5 \(\rightarrow\) 0,5 \(\rightarrow\) 0,5
\(b.V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2l\)
\(c.C_{M_{ddH_2SO_4}}=n_{H_2SO_4}.V_{dd_{H_1SO_4}}=0,5.0,1=0,05M\)
a, PT: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
b, Ta có: \(n_{Fe}=\dfrac{19,6}{56}=0,35\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Fe}=0,35\left(mol\right)\Rightarrow V_{H_2}=0,35.22,4=7,84\left(l\right)\)
c, \(n_{H_2SO_4}=n_{Fe}=0,35\left(mol\right)\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,35}{0,2}=1,75\left(M\right)\)
d, \(n_{FeSO_4}=n_{Fe}=0,35\left(mol\right)\Rightarrow m_{FeSO_4}=0,35.152=53,2\left(g\right)\)
e, \(C_{M_{FeSO_4}}=\dfrac{0,35}{0,2}=1,75\left(M\right)\)
d, \(n_{H_2SO_4}=0,25.1,6=0,4\left(mol\right)\)
Xét tỉ lệ: \(\dfrac{n_{Fe}}{1}< \dfrac{n_{H_2SO_4}}{1}\), ta được H2SO4 dư.
Theo PT: \(n_{H_2SO_4\left(pư\right)}=n_{Fe}=0,35\left(mol\right)\)
\(\Rightarrow n_{H_2SO_4\left(dư\right)}=0,4-0,35=0,05\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4\left(dư\right)}=0,05.98=4,9\left(g\right)\)
\(a,Zn+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2\\ n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ b,n_{CH_3COOH}=2.0,2=0,4\left(mol\right)\\ C_{MddCH_3COOH}=\dfrac{0,4}{0,4}=1\left(M\right)\\ c,CH_3COOH+KOH\rightarrow CH_3COOK+H_2O\\ n_{CH_3COOK}=n_{CH_3COOH}=0,4\left(mol\right)\\ V_{ddCH_3COOK}=400+400=800\left(ml\right)=0,8\left(l\right)\\ C_{MddCH_3COOK}=\dfrac{0,4}{0,8}=0,5\left(M\right)\)
\(Zn+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2\uparrow\)
0,4 0,2
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
\(b,C_{M_{CH_3COOH}}=\dfrac{0,4}{0,4}=1M\)
\(c,CH_3COOH+KOH\rightarrow CH_3COOK+H_2O\)
0,4 0,4 0,4
\(C_{M_{CH_3COOK}}=\dfrac{0,4}{0,4}=1M\)