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PTHH: \(CuCl_2+2NaOH\rightarrow2NaCl+Cu\left(OH\right)_2\downarrow\)
\(Cu\left(OH\right)_2\xrightarrow[]{t^o}CuO+H_2O\)
Ta có: \(n_{CuCl_2}=0,2\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}n_{Cu\left(OH\right)_2}=0,2\left(mol\right)=n_{CuO}\\n_{NaOH}=0,4\left(mol\right)=n_{NaCl}\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Cu\left(OH\right)_2}=0,2\cdot98=19,6\left(g\right)\\m_{CuO}=0,2\cdot80=16\left(g\right)\\m_{NaCl}=0,4\cdot58,5=23,4\left(g\right)\\C\%_{NaOH}=\dfrac{0,4\cdot40}{200}\cdot100\%=8\%\end{matrix}\right.\)
Ta có: \(n_{NaOH}=\dfrac{12}{40}=0,3\left(mol\right)\)
PT: \(2NaOH+CuCl_2\rightarrow2NaCl+Cu\left(OH\right)_{2\downarrow}\)
_____0,3_______________________0,15 (mol)
\(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)
0,15_______0,15 (mol)
⇒ m = mCuO = 0,15.80 = 12 (g)
Bạn tham khảo nhé!
\(n_{NaOH}=\dfrac{200.10\%}{40}=0,5\left(mol\right)\)
\(PTHH:CuCl_2+2NaOH\rightarrow2NaCl+Cu\left(OH\right)_2\)
bđ: 0,3 0,5
pứ: 0,25 0,5 0,5 0,25
[ ]: 0,05 0 0,5 0,25
\(PTHH:Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)
(mol) 0,25 0,25
\(a.m_C=80.0,25=20\left(g\right)\)
\(b.m_{NaCl}=58,5.0,5=29,25\left(g\right)\\ m_{Cu\left(OH\right)_2}=0,25.98=24,5\left(g\right)\\ m_{CuCl_2\left(du\right)}=135.0,05=6,75\left(g\right)\)
\(c.m_{ddspu}=100+200-24,5=275,5\left(g\right)\\ C\%_{ddCuCl_2\left(du\right)}=\dfrac{135.0,05}{275,5}.100=2,45\left(\%\right)\\ C\%_{ddNaCl}=\dfrac{0,5.58,5}{275,25}.100=10,62\left(\%\right)\)
\(n_{CuSO_4}=2.0,34=0,68(mol)\\ a,CuSO_4+2NaOH\to Na_2SO_4+Cu(OH)_2\downarrow\\ Cu(OH)_2\xrightarrow{t^o}CuO+H_2O\\ \Rightarrow n_{Cu(OH)_2}=0,68(mol)\\ \Rightarrow m_{Cu(OH)_2}=0,68.98=66,64(g)\\ b,n_{CuO}=0,68(mol)\\ \Rightarrow m_{CuO}=0,68.80=54,4(g)\\ c,V_{dd_{NaOH}}=\dfrac{200}{1,25}=160(ml)\\ n_{NaOH}=\dfrac{200.32\%}{100\%.40}=1,6(mol)\)
Vì \(\dfrac{n_{CuSO_4}}{1}<\dfrac{n_{NaOH}}{2}\) nên \(NaOH\) dư
\(\Rightarrow n_{NaOH(dư)}=1,6-0,68.2=0,24(mol); n_{Na_2SO_4}=0,68(mol)\\ \Rightarrow \begin{cases} C_{M_{NaOH(dư)}}=\dfrac{0,24}{0,16}=1,5M\\ C_{M_{Na_2SO_4}}=\dfrac{0,68}{0,16}=4,25M \end{cases}\)
a) \(CuSO_4+2NaOH\rightarrow Cu\left(OH\right)_2+Na_2SO_4\)
b) \(n_{CuSO_4}=0,4.1=0,4\left(mol\right)\)
\(n_{NaOH}=\dfrac{40}{40}=1\left(mol\right)\)
Xét tỉ lệ: \(\dfrac{0,4}{1}< \dfrac{1}{2}\) => CuSO4 hết, NaOH dư
PTHH: CuSO4 + 2NaOH --> Cu(OH)2 + Na2SO4
_______0,4----->0,8---------->0,4-------->0,4
Cu(OH)2 --to--> CuO + H2O
0,4------------->0,4
=> mCuO = 0,4.80 = 32 (g)
c) \(\left\{{}\begin{matrix}m_{NaOH\left(dư\right)}=\left(1-0,8\right).40=8\left(g\right)\\m_{Na_2SO_4}=0,4.142=56,8\left(g\right)\end{matrix}\right.\)
\(n_{CuCl_2}=2.0,2=0,4(mol)\\ n_{NaOH}=2.0,2=0,4(mol)\\ a,CuCl_2+2NaOH\to Cu(OH)_2+2NaCl\\ Cu(OH)_2\xrightarrow{t^o}CuO+H_2O\\ b,\dfrac{n_{CuCl_2}}{1}>\dfrac{n_{NaOH}}{2}\Rightarrow CuCl_2\text{ dư}\\ \Rightarrow n_{CuO}=0,2(mol)\\ \Rightarrow m_{CuO}=0,2.80=16(g)\\ c,n_{CuCl_2(dư)}=0,4-0,2=0,2(mol)\\n_{NaCl}=0,2(mol)\\ \Rightarrow m_{CuCl_2(dư)}=0,2.135=27(g)\\ m_{NaCl}=0,2.58,5=11,7(g)\)
PTHH: \(CuCl_2+2NaOH\rightarrow2NaCl+Cu\left(OH\right)_2\downarrow\)
\(Cu\left(OH\right)_2\xrightarrow[]{t^o}CuO+H_2O\)
Ta có: \(\left\{{}\begin{matrix}n_{CuCl_2}=0,2\cdot2=0,4\left(mol\right)\\n_{NaOH}=0,2\cdot2=0,4\left(mol\right)\end{matrix}\right.\)
Xét tỉ lệ: \(\dfrac{0,4}{1}>\dfrac{0,4}{2}\) \(\Rightarrow\) CuCl2 còn dư
\(\Rightarrow\left\{{}\begin{matrix}n_{NaCl}=0,4\left(mol\right)\\n_{Cu\left(OH\right)_2}=0,2\left(mol\right)=n_{CuO}=n_{CuCl_2\left(dư\right)}\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{CuO}=0,2\cdot80=16\left(g\right)\\C_{M_{NaCl}}=\dfrac{0,4}{0,2+0,2}=1\left(M\right)\\C_{M_{CuCl_2}}=\dfrac{0,2}{0,4}=0,5\left(M\right)\\\end{matrix}\right.\)
a) mNaOH= 200.20%= 40(g)
=>nNaOH=1(mol)
PTHH: 2 NaOH + CuCl2 -> 2 NaCl + Cu(OH)2
Dung dịch sau khi lọc kết tủa có NaCl.
nNaCl=nNaOH= 1(mol)
nCuCl2=nCu(OH)2=nNaOH/2=1/2=0,5(mol)
mNaCl=1.58,5=58,5(g)
mCuCl2=0,5.135=67,5(g)
=> mddCuCl2=(67,5.100)/10=675(g)
mCu(OH)2=0,5.98=49(g)
=>mddNaCl=mddNaOH+ mddCuCl2 - mCu(OH)2= 200+675 - 98=777(g)
=> \(C\%ddNaCl=\dfrac{58,5}{777}.100\approx7,529\%\)
b) PTHH: Cu(OH)2 -to-> CuO + H2O
0,5__________________0,5(mol)
m(rắn)=mCuO=0,5.80=4(g)
nCuCl2 = 1 . 2 = 2 mol
nNaOH = \(\dfrac{400.50}{100.40}\) = 5 mol
CuCl2 +2 NaOH -> Cu(OH)2 \(\downarrow\) + 2NaCl
2(hết);5mol(dư)--->2mol
Cu(OH)2 \(^{to}\rightarrow\) CuO + H2O
2mol------------>2mol
=>mCu = 2 . 64 = 128 g