Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài 2:
a) PTHH: \(Na_2O+H_2O\rightarrow2NaOH\)
b) Dung dịch A là dung dịch bazơ
Ta có: \(n_{Na_2O}=\dfrac{3,1}{62}=0,05\left(mol\right)\) \(\Rightarrow n_{NaOH}=0,1\left(mol\right)\) \(\Rightarrow C_{M_{NaOH}}=\dfrac{0,1}{1}=0,1\left(M\right)\)
c) Sửa đề: dd H2SO4 9,8%
PTHH: \(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
Theo PTHH: \(n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}=0,05\left(mol\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,05\cdot98}{9,8\%}=50\left(g\right)\) \(\Rightarrow V_{ddH_2SO_4}=\dfrac{50}{1,14}\approx43,86\left(ml\right)\)
Bài 1:
PTHH: \(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)
Ta có: \(\left\{{}\begin{matrix}n_{CuO}=\dfrac{16}{80}=0,2\left(mol\right)\\n_{H_2SO_4}=\dfrac{200\cdot19,6\%}{98}=0,4\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Axit còn dư
\(\Rightarrow n_{CuSO_4}=0,2\left(mol\right)=n_{H_2SO_4\left(dư\right)}\)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{CuSO_4}=\dfrac{0,2\cdot160}{200+16}\cdot100\%\approx14,81\%\\C\%_{H_2SO_4\left(dư\right)}=\dfrac{0,2\cdot98}{200+16}\cdot100\%\approx9,07\%\end{matrix}\right.\)
\(n_{CuO}=\frac{16}{80}=0,2\left(mol\right)\)
\(m_{H_2SO_4}=\frac{200.19,6}{100}=39,2\left(g\right)\) => \(n_{H_2SO_4}=\frac{39,2}{98}=0,4\left(mol\right)\)
PTHH: \(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)
_______0,2------>0,2---------->0,2____________(mol)
=> \(\left\{{}\begin{matrix}m_{CuSO_4}=0,2.160=32\left(g\right)\\m_{H_2SO_4\left(dư\right)}=\left(0,4-0,2\right).98=19,6\left(g\right)\end{matrix}\right.\)
=> \(\left\{{}\begin{matrix}C\%\left(CuSO_4\right)=\frac{32}{16+200}.100\%=14,8\%\\C\%\left(H_2SO_4\right)=\frac{19,6}{16+200}.100\%=9,07\%\end{matrix}\right.\)
a, \(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)
\(FeCl_3+3KOH\rightarrow3KCl+Fe\left(OH\right)_{3\downarrow}\)
\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)
Theo PT: \(n_{HCl}=6n_{Fe_2O_3}=0,6\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\)
b, \(n_{Fe\left(OH\right)_3}=n_{FeCl_3}=2n_{Fe_2O_3}=0,2\left(mol\right)\)
\(\Rightarrow m_{Fe\left(OH\right)_3}=0,2.107=21,4\left(g\right)\)
\(n_{KOH}=3n_{FeCl_3}=0,6\left(mol\right)\)
\(\Rightarrow C_{M_{KOH}}=\dfrac{0,6}{0,2}=3\left(M\right)\)
CuO + 2HCl → CuCl2 + H2O (1)
Fe2O3 + 6HCl → 2FeCl3 + 3H2O (2)
\(n_{HCl}=0,2\times3,5=0,7\left(mol\right)\)
Gọi x,y lần lượt là số mol của CuO và Fe2O3
Ta có: \(80x+160y=20\) (*)
Theo PT1: \(n_{HCl}=2n_{CuO}=2x\left(mol\right)\)
Theo pT2: \(n_{HCl}=6n_{Fe_2O_3}=6y\left(mol\right)\)
Ta có: \(2x+6y=0,7\) (**)
Từ (*)(**) ta có: \(\left\{{}\begin{matrix}80x+160y=20\\2x+6y=0,7\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,05\\y=0,1\end{matrix}\right.\)
Vậy \(n_{CuO}=0,05\left(mol\right)\Rightarrow m_{CuO}=0,05\times80=4\left(g\right)\)
\(n_{Fe_2O_3}=0,1\left(mol\right)\Rightarrow m_{Fe_2O_3}=0,1\times160=16\left(g\right)\)
\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ n_{H_2SO_4}=n_{CuO}=\dfrac{19,6}{98}=0,2\left(mol\right)\\ \Rightarrow a=m_{CuO}=0,2\cdot80=16\left(g\right)\)
n H2SO4 = \(\dfrac{19,6}{2+32+16.4}=0,2mol\)
\(CuO+H_2SO_4->CuSO_4+H_2O\)
0,2..........0,2
m CuO = 0,2.(64+16)=16 g
Vậy a =16
\(PTHH:2CH_3COOH+CuO\rightarrow\left(CH_3COO\right)_2+H_2O\)
0,4 mol 0,2 mol
n\(_{CuO}\)=\(\frac{16}{80}\)=0,2(mol)
m\(_{CH_3COOH}\)=0,4 . 60=24(g)
C%\(_{CH_3COOH}\)=\(\frac{m_{ct}}{m_{dd}}\)x 100%=\(\frac{24}{200}.100\%\)=12%
PTHH:\(2CH_3COOH+CuO\rightarrow\left(CH_3COOH\right)_2Cu+H_2O\)