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a) Zn + 2HCl --> ZnCl2 + H2
Hiện tượng: Kẽm tan dần, sủi bọt khí
b)
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\); \(n_{HCl}=\dfrac{10,95}{36,5}=0,3\left(mol\right)\)
PTHH: Zn + 2HCl --> ZnCl2 + H2
Xét tỉ lệ: \(\dfrac{0,1}{1}< \dfrac{0,3}{2}\) => Zn hết, HCl dư
c)
PTHH: Zn + 2HCl --> ZnCl2 + H2
0,1------------>0,1--->0,1
=> VH2 = 0,1.22,4 = 2,24 (l)
mZnCl2 = 0,1.136 = 13,6 (g)
Câu 1:
a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, \(n_{Zn}=\dfrac{16,25}{65}=0,25\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Zn}=0,25\left(mol\right)\Rightarrow V_{H_2}=0,25.22,4=5,6\left(l\right)\)
c, \(n_{HCl}=2n_{Zn}=0,5\left(mol\right)\Rightarrow m_{Zn}=0,5.36,5=18,25\left(g\right)\)
Câu 2:
a, \(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
b, \(n_P=\dfrac{1,24}{31}=0,04\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{5}{4}n_P=0,05\left(mol\right)\Rightarrow V_{O_2}=0,05.22,4=1,12\left(l\right)\)
c, \(n_{P_2O_5}=\dfrac{1}{2}n_P=0,02\left(mol\right)\Rightarrow m_{P_2O_5}=0,02.142=2,84\left(g\right)\)
\(n_{HCl}=\dfrac{25}{36,5}=\dfrac{50}{73}mol\)
2Al + 6HCl \(\rightarrow\) 2AlCl3 + 3H2
\(\Rightarrow n_{Al}=\dfrac{\dfrac{50}{73}.2}{6}=\dfrac{50}{219}mol\\ m_{Al}=\dfrac{50}{219}.27=\dfrac{450}{73}g\)
\(n_{H_2}=\dfrac{\dfrac{50}{73}.3}{6}=\dfrac{25}{73}mol\\ V_{H_2}=\dfrac{25}{73}.22,4=\dfrac{560}{73}l\)
a: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
b: \(n_{HCl}=\dfrac{25}{36.5}=\dfrac{50}{73}\left(mol\right)\)
\(\Leftrightarrow n_{AlCl_3}=\dfrac{150}{73}\left(mol\right)=n_{Al}\)
\(m_{Al}=\dfrac{150}{73}\cdot27=\dfrac{4050}{73}\left(g\right)\)
\(n_{Zn}=\dfrac{32,5}{65}=0,5(mol)\\ a,PTHH:Zn+2HCl\to ZnCl_2+H_2\\ b,n_{H_2}=n_{Zn}=0,5(mol)\\ \Rightarrow V_{H_2(phản ứng)}=0,5.22,4=11,2(l)\\ \Rightarrow V_{H_2(thực tế)}=11,2.80\%=8,96(l)\)
\(a/Fe+2HCl\xrightarrow[]{}FeCl_2+H_2\\ b/n_{H_2}=n_{FeCl_2}=0,1mol\\ m_{FeCl_2}=0,1.127=12,7\left(g\right)\\ c/V_{H_2}=0,1.22,4=2,24\left(l\right)\\ d/n_{HCl}=0,1.2=0,2\left(mol\right)\\ V_{HCl\left(pư\right)}=\dfrac{0,2}{2}=0,1\left(l\right)\)
\(c,V_{H_2}=0,1.22,4=2,24\left(l\right)\)
Còn lại giống câu dưới nha
Bài 1.
a/ PTHH: Zn + 2HCl ===> ZnCl2 + H2
b/ nZn = 32,5 / 65 = 0,5 mol
=> nH2 = nZn = 0,5 mol
=> VH2(đktc) = 0,5 x 22,4 = 11,2 lít
Bài 2/
a/ PTHH: 2Al + 6HCl ==> 2AlCl3 + 3H2
b/ nAl = 4,05 / 27 = 0,15 mol
=> nH2 = 0,225 mol
=> VH2(đktc) = 0,225 x 22,4 = 5,04 lít
=> nAlCl3 = 0,15 mol
=> mAlCl3 = 0,15 x 133,5 = 20,025 gam
\(n_{Zn}=\dfrac{8,125}{65}=0,125\left(mol\right)\\ m_{HCl}=\dfrac{100.18,25}{100}=18,25\left(g\right)\\
n_{HCl}=\dfrac{18,25}{36,5}=0,5\\ pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
0,125 0,125 (mol )
\(\Rightarrow V_{H_2}=0,125.22,4=2,8\left(l\right)\\
\)
\(C\%=\dfrac{8,125}{8,125+18,25}.100\%=30,8\%\)
Bài 18:
Ta có: \(n_{Zn}=\dfrac{8,125}{65}=0,125\left(mol\right)\)
\(m_{HCl}=100.18,25\%=18,25\left(g\right)\Rightarrow n_{HCl}=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)
a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, Xét tỉ lệ: \(\dfrac{0,125}{1}< \dfrac{0,5}{2}\), ta được HCl dư.
Theo PT: \(n_{H_2}=n_{Zn}=0,125\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,125.22,4=2,8\left(g\right)\)
\(m_{H_2}=0,125.2=0,25\left(g\right)\)
c, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,125\left(mol\right)\\n_{HCl\left(pư\right)}=2n_{Zn}=0,25\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow n_{HCl\left(dư\right)}=0,25\left(mol\right)\)
Có: m dd sau pư = 8,125 + 100 - 0,25 = 107,875 (g)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{ZnCl_2}=\dfrac{0,125.136}{107,875}.100\%\approx15,76\%\\C\%_{HCl\left(dư\right)}=\dfrac{0,25.36,5}{107,875}.100\%\approx8,46\%\end{matrix}\right.\)
Bạn tham khảo nhé!
a) Zn + 2HCl --> ZnCl2 + H2
b) \(n_{H_2}=\dfrac{22,4}{22,4}=1\left(mol\right)=>m_{H_2}=1.2=2\left(g\right)\)
Theo ĐLBTKL:
\(m_{Zn}+m_{HCl}=m_{ZnCl_2}+m_{H_2}\)
=> \(m_{HCl}=136+2-65=73\left(g\right)\)
\(a,PTHH:Zn+2HCl\to ZnCl_2+H_2\\ b,m_{H_2}=\dfrac{22,4}{22,4}.2=2(g)\\ BTKL:m_{Zn}+m_{HCl}=m_{ZnCl_2}+m_{H_2}\\ \Rightarrow m_{HCl}=136+2-65=73(g)\)