Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
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
\(V_{O_2}=0,05.22,4=1,12\left(l\right)\)
\(\Rightarrow V_{không.khí}=1,12.5=5,6\left(l\right)\)
a) $Fe + 2HCl \to FeCl_2 + H_2$
Theo PTHH : n H2 = n Fe = 8,4/56 = 0,15(mol)
V H2 = 0,15.22,4 = 3,36(lít)
b) n HCl = 2n Fe = 0,3(mol)
=> CM HCl = 0,3/0,2 = 1,5M
c) $CuO + H_2 \xrightarrow{t^o} Cu + H_2O$
Ta thấy :
n CuO = 32/80 = 0,4 > n H2 = 0,15 mol nên CuO dư
Theo PTHH : n Cu = n H2 = 0,15 mol
=> m Cu = 0,15.64 = 9,6 gam
a+b+c) PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)=n_{ZnCl_2}=n_{H_2}\)
\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,1\cdot136=13,6\left(g\right)\\V_{H_2}=0,1\cdot22,4=2,24\left(l\right)\end{matrix}\right.\)
d) PTHH: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)
Theo PTHH: \(n_{H_2}=n_{Cu}=0,1\left(mol\right)\)
\(\Rightarrow m_{Cu}=0,1\cdot64=6,4\left(g\right)\)
a. \(PTHH:Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)
\(n_{Mg}=\dfrac{m_{Mg}}{M_{Mg}}=\dfrac{12}{24}=0,5\left(mol\right)\)
- Mol theo PTHH : \(1:2:1:1\)
- Mol theo phản ứng : \(0,5\rightarrow1\rightarrow0,5\rightarrow0,5\)
\(\Rightarrow n_{H_2}=0,5\left(mol\right)\)
\(\Rightarrow V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)
b. Từ a. \(\Rightarrow n_{HCl}=1\left(mol\right)\)
\(\Rightarrow m_{HCl}=n_{HCl}.M_{HCl}=1.\left(1+35,5\right)=36,5\left(g\right)\)
c. \(n_{O_2}=\dfrac{V_{O_2}}{22,4}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
\(PTHH:2H_2+O_2\underrightarrow{t^o}2H_2O\)
- Mol theo PTHH : \(2:1:2\)
- Mol theo phản ứng : \(0,6\leftarrow0,3\rightarrow0,6\)
\(\Rightarrow n_{H_2O}=0,6\left(mol\right)\)
\(\Rightarrow m_{H_2O}=n_{H_2O}.M_{H_2O}=0,6.\left(2+16\right)=10,8\left(g\right)\)
a) Zn + 2HCl →ZnCl2 + H2
b) nZn = 6,5/65 = 0,1 mol . Theo tỉ lệ pư => nH2 = nZn = nZnCl2 =0,1 mol <=> VH2(đktc) = 0,1.22,4 = 2,24 lít.
c) mZnCl2 = 0,1 . 136 = 13,6 gam
d) nHCl =2nZn = 0,2 mol => mHCl = 0,2.36,5= 7,3 gam
Cách 2: áp dụng định luật BTKL => mHCl = mZnCl2 + mH2 - mZn
<=> mHCl = 13,6 + 0,1.2 - 6,5 = 7,3 gam
\(n_{H_2}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(.........0.6............0.3\)
\(C_{M_{HCl}}=\dfrac{0.6}{0.3}=2\left(M\right)\)
\(n_{Fe_2O_3}=\dfrac{48}{160}=0.3\left(mol\right)\)
\(Fe_2O_3+3H_2\underrightarrow{^{t^0}}2Fe+3H_2O\)
\(1..............3\)
\(0.3..........0.3\)
\(LTL:\dfrac{0.3}{1}>\dfrac{0.3}{3}\Rightarrow Fe_2O_3dư\)
\(n_{Fe}=\dfrac{2}{3}n_{H_2}=\dfrac{2}{3}\cdot0.3=0.2\left(mol\right)\)
\(m_{Fe}=0.2\cdot56=11.2\left(g\right)\)
Theo gt ta có: $n_{Zn}=0,1(mol)$
a, $Zn+2HCl\rightarrow ZnCl_2+H_2$
b, Ta có: $n_{H_2}=0,1(mol)\Rightarrow V_{H_2}=2.24(l)$
c, Ta có: $n_{HCl}=2.n_{Zn}=0,2(mol)\Rightarrow m_{HCl}=7,3(g)$
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
0,1 0,4
0,1 0,2
0 0,2 0,1 0,1
\(a,V_{H_2}=0,1.22,4=2,24\left(l\right)\\ b,m_{dd}=6,5+0,4.36,5+50-0,1.2=70,9\left(g\right)\\ C\%_{ZnCl_2}=\dfrac{0,1.136}{70,9}.100\%=19,18\%\)
Bài 1.
\(n_{Ba}=\dfrac{13,7}{137}=0,1mol\)
\(n_{H_2O}=\dfrac{90}{18}=5mol\)
\(Ba+2H_2O\rightarrow Ba\left(OH\right)_2+H_2\)
0,1 5 0,1
\(m_{Ba\left(OH\right)_2}=0,1\cdot171=17,1g\)
\(m_{ddBa\left(OH\right)_2}=13,7+90-0,1\cdot18=101,9g\)
\(C\%=\dfrac{17,1}{101,9}\cdot100\%=16,78\%\)
Bài 2.
\(m_{H_2SO_4}=\dfrac{200\cdot9,8\%}{100\%}=19,6g\Rightarrow n_{H_2SO_4}=0,2mol\)
\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\uparrow\)
0,2 0,2 0,2
\(m_{FeSO_4}=0,2\cdot152=30,4g\)
\(V_{H_2}=0,2\cdot22,4=4,48l\)
a) \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PTHH: Zn + 2HCl --> ZnCl2 + H2
0,1-->0,2------>0,1-->0,1
=> VH2 = 0,1.22,4 = 2,24 (l)
mZnCl2 = 0,1.136 = 13,6 (g)
b) \(C\%_{dd.HCl}=\dfrac{0,2.36,5}{200}.100\%=3,65\%\)
c) \(n_{O_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
PTHH: 2H2 + O2 --to--> 2H2O
Xét tỉ lệ: \(\dfrac{0,1}{2}< \dfrac{0,15}{1}\) => H2 hết, O2 dư
PTHH: 2H2 + O2 --to--> 2H2O
0,1--------------->0,1
=> mH2O = 0,1.18 = 1,8 (g)