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a, \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
\(m_{HCl}=200.14,6\%=29,2\left(g\right)\Rightarrow n_{HCl}=\dfrac{29,2}{36,5}=0,8\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Xét tỉ lệ: \(\dfrac{0,3}{1}< \dfrac{0,8}{2}\), ta được HCl dư.
Theo PT: \(n_{H_2}=n_{Zn}=0,3\left(mol\right)\Rightarrow V_{H_2}=0,3.22,4=6,72\left(l\right)\)
b, \(n_{ZnCl_2}=n_{Zn}=0,3\left(mol\right)\Rightarrow m_{ZnCl_2}=0,3.136=40,8\left(g\right)\)
c, \(n_{HCl\left(pư\right)}=2n_{Zn}=0,6\left(mol\right)\Rightarrow n_{HCl\left(dư\right)}=0,2\left(mol\right)\)
Ta có: m dd sau pư = 19,5 + 200 - 0,3.2 = 218,9 (g)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{HCl}=\dfrac{0,2.36,5}{218,9}.100\%\approx3,33\%\\C\%_{ZnCl_2}=\dfrac{40,8}{218,9}.100\%\approx18,64\%\end{matrix}\right.\)
\(a)n_{Zn}=\dfrac{19,5}{65}=0,3mol\\ n_{HCl}=\dfrac{200.14,6}{100.36,5}=0,8mol\\ Zn+2HCl\rightarrow ZnCl_2+H_2\\ \Rightarrow\dfrac{0,3}{1}< \dfrac{0,8}{2}\Rightarrow HCl.dư\\ n_{H_2}=n_{ZnCl_2}=n_{Zn}=0,3mol\\ V_{H_2}=0,3.22,4=6,72l\\ b)m_{ZnCl_2}=0,3.136=40,8g\\ c)n_{HCl.pư}=0,3.2=0,6mol\\ C_{\%ZnCl_2}=\dfrac{40,8}{200+19,5-0,3.2}\cdot100=18,64\%\\ C_{\%HCl.dư}=\dfrac{\left(0,8-0,6\right).36,5}{200+19,5-0,3.2}\cdot100=3,33\%\)
PTHH: \(MgO+2HCl\rightarrow MgCl_2+H_2O\)
a_____2a_______a_______a (mol)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
b_____6b_______2b_______3b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}40a+102b=18,2\\2a+6b=\dfrac{182,5\cdot20\%}{36,5}=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{MgO}=\dfrac{0,2\cdot40}{18,2}\cdot100\%\approx43,96\%\\\%m_{Al_2O_3}=56,04\%\end{matrix}\right.\)
Theo PTHH: \(n_{MgCl_2}=0,2\left(mol\right)=n_{AlCl_3}\) \(\Rightarrow\left\{{}\begin{matrix}m_{MgCl_2}=0,2\cdot95=19\left(g\right)\\m_{AlCl_3}=0,2\cdot133,5=26,7\left(g\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{MgCl_2}=\dfrac{19}{18,2+182,5}\cdot100\%\approx9,47\%\\C\%_{AlCl_3}=\dfrac{26,7}{182,5+18,2}\cdot100\%\approx13,3\%\end{matrix}\right.\)
a) mHCl=182,5. 20%=36,5(g) -> nHCl=1(mol)
Đặt nMgO=a(mol); nAl2O3=b(mol)
PTHH: MgO +2 HCl -> MgCl2 + H2O
a__________2a______a(mol)
Al2O3 + 6 HCl -> 2 AlCl3 + 3 H2O
b_______6b______2b(mol)
b) Ta có hpt:
\(\left\{{}\begin{matrix}40a+102b=18,2\\2a+6b=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\)
=> mMgO=0,2.40=8(g)
=>%mMgO=(8/18,2).100=43,956%
=> %mAl2O3= 56,044%
c) m(muối)= mAlCl3 + mMgCl2= 133,5.2b+ 95.a= 133,5.0,1.2+95.0,2= 45,7(g)
d) mAlCl3= 26,7(g) ; mMgCl2 = 19(g)
mddsau= 18,2+ 182,5= 200,7(g)
=>C%ddAlCl3=(26,7/200,7).100=13,303%
C%ddMgCl2=(19/200,7).100=9,467%
Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
\(a.PTHH:Zn+H_2SO_4--->ZnSO_4+H_2\uparrow\)
b. Theo PT: \(n_{ZnSO_4}=n_{H_2}=n_{Zn}=0,1\left(mol\right)\)
\(\Rightarrow m_{ZnSO_4}=0,1.161=16,1\left(g\right)\)
\(V_{H_2}=0,1.22,4=2,24\left(lít\right)\)
c. Theo PT: \(n_{H_2SO_4}=n_{Zn}=0,1\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4}=0,1.98=9,8\left(g\right)\)
Ta có: \(C_{\%_{H_2SO_4}}=\dfrac{9,8}{m_{dd_{H_2SO_4}}}.100\%=20\%\)
\(\Rightarrow m_{dd_{H_2SO_4}}=49\left(g\right)\)
Câu 1 :
\(n_{HCl}=\dfrac{73\cdot20\%}{36.5}=0.4\left(mol\right)\)
\(CuO+2HCl\rightarrow CuCl_2+H_2O\)
\(..........0.4.......0.2\)
\(m_{CuCl_2}=0.2\cdot135=27\left(g\right)\)
Câu 2 :
\(n_{Fe_2O_3}=\dfrac{2.4}{160}=0.015\left(mol\right)\)
\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)
\(0.015...........................0.015\)
\(m_{dd}=2.4+300=302.4\left(g\right)\)
\(C\%_{Fe_2\left(SO_4\right)_3}=\dfrac{0.015\cdot400}{302.4}\cdot100\%=1.98\%\)
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: \(n_{H_2SO_4\left(pư\right)}=n_{Fe}=0,35\left(mol\right)\)
\(\Rightarrow n_{H_2SO_4\left(dư\right)}=0,4-0,35=0,05\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4\left(dư\right)}=0,05.98=4,9\left(g\right)\)
Ừm , mình nhớ hôm qua bài này , bạn đã đăng rồi và mình cũng đã trả lời cho bạn . Bạn xem lại nhé
nHCl=0.4*1=0.4(mol)
pthh:CuO+2HCl->CuCl2+H2O(1)
MgO+2HCl->MgCl2+H2O(2)
gọi nCuO là x(mol)->nHCl(1)=2x(mol)
nMgO là y(mol)->nHCl(2)=2y(mol)
theo bài ra ta có:80x+40y=12(g)
2x+2y=0.4
Giải hệ ta được x=
x=y=0.1(mol)
->mCuO=0.1*80=8(g)%CuO=8:12*100 = 67%
mMgO=0.1*40=4(g)%MgO=4:12*100=33%
câu b chỉ tính được CM thôi bạn ơi,bạn xem lại đề bài nhé ^^ phải có khối lượng riêng của dd mới tính được C%
\(a,PTHH:CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ n_{CuSO_4}=n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\\ \Rightarrow m_{CuSO_4}=0,1\cdot160=16\left(g\right)\\ b,n_{H_2SO_4}=n_{CuO}=0,1\left(mol\right)\\ \Rightarrow m_{CT_{H_2SO_4}}=0,1\cdot98=9,8\left(g\right)\\ \Rightarrow C\%_{H_2SO_4}=\dfrac{9,8}{200}\cdot100\%=4,9\%\)
PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Ta có: \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}n_{HCl}=0,6\left(mol\right)\\n_{ZnCl_2}=0,3\left(mol\right)=n_{H_2}\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,3\cdot136=40,8\left(g\right)\\m_{ddHCl}=\dfrac{0,6\cdot36,5}{20\%}=109,5\left(g\right)\\m_{H_2}=0,3\cdot2=0,6\left(g\right)\end{matrix}\right.\)
\(\Rightarrow C\%_{ZnCl_2}=\dfrac{40,8}{19,5+109,5-0,6}\cdot100\%\approx37,78\%\)