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\(a,PTHH:2Al+3X_2\rightarrow2AlX_3\\ Theo.ĐLBTKL,ta.có:\\ m_{Al}+m_{X_2}=m_{AlX_3}\\ \Leftrightarrow m_{Al}+33,6=37,38\\ \Leftrightarrow m_{Al}=3,78\left(g\right)\\ \Rightarrow n_{Al}=\dfrac{3,78}{27}=0,14\left(mol\right)\\ n_{X_2}=\dfrac{3}{2}.0,14=0,21\left(mol\right)\\ \Rightarrow M_{X_2}=\dfrac{33,6}{0,21}=160\left(\dfrac{g}{mol}\right)\\ \Rightarrow M_X=80\left(\dfrac{g}{mol}\right)\\ \Rightarrow X:Brom\left(Br=80\right)\\ b,n_{AlBr_3}=\dfrac{42,72}{267}=0,16\left(mol\right)\\ AlBr_3+3AgNO_3\rightarrow Al\left(NO_3\right)_3+3AgBr\downarrow\left(vàng.nhạt\right)\\ n_{AgBr}=n_{AgNO_3}=0,16.3=0,48\left(mol\right)\\ \Rightarrow m_T=m_{\downarrow}=m_{AgBr}=188.0,48=90,24\left(g\right)\)
\(m_{ddZ}=42,72+447,52-90,24=400\left(g\right)\\ n_{Al\left(NO_3\right)_3}=n_{AlBr_3}=0,16\left(mol\right)\\ \Rightarrow C\%_{ddZ}=C\%_{ddAl\left(NO_3\right)_3}=\dfrac{0,16.213}{400}.100=8,52\%\)
\(c,n_{Br_2}=\dfrac{12,8}{160}=0,08\left(mol\right)\\ 2NaI+Br_2\rightarrow2NaBr+I_2\\ n_{I_2}=n_{Br_2}=0,08\left(mol\right);n_{NaI}=2.0,08=0,16\left(mol\right)\\ \Rightarrow x=C_{MddNaI}=\dfrac{0,16}{0,25}=0,64\left(M\right)\\ m_{I_2}=0,08.254=20,32\left(g\right)\)
X + AgNO3\(\rightarrow\)kết tủa AgCl + muối Y
Kết tủa là AgCl\(\rightarrow\) nAgCl=\(\frac{22,96}{\text{108+35,5}}\)=0,16 mol
Bảo toàn Ag: nAgCl=nAgNO3=0,16 mol
\(\rightarrow\)mAgNO3=0,16.(108+62)=27,2 gam
BTKL: mX + mAgNO3=mAgCl + mY
\(\rightarrow\)9,3+27,2=22,96+mY\(\rightarrow\)mY=13,54 gam
a)nCl2=0,3mol=>mCl2=21,3g
Định luật bảo tòan khối lượng:ma=mB-mCl2=29,6-21,3=8,3g
b)nCl-=2.0,3=0,6mol=>nAgCl=0,6mol=>mC=0,6.143,5=86,1g
nAg+=nCl-=0,6mol=>nAgNO3=0,6mol=>VAgNO3=\(\dfrac{0,6}{2}\)=0,3lít
1/
gọi tên halogen đó là X,ta có:
ZnX\(_2\)+2\(AgNO_3\)→Zn\(\left(NO_3\right)_2\)+2AgX
dựa vào phương trình ta có:
\(\dfrac{32,64}{65+2_{MX}}\)=\(\dfrac{68,88}{2.\left(108+M_x\right)}\)
⇔\(M_x\)=35,5
→clo(Cl)
vậy muối đó là:ZnCl\(_2\)
Câu 1:
Gọi \(\left\{{}\begin{matrix}n_{Cu}:x\left(mol\right)\\n_{Fe}:y\left(mol\right)\end{matrix}\right.\)
\(Cu+Cl_2\rightarrow CuCl_2\)
\(Fe+Cl_2\rightarrow FeCl_2\)
\(\left\{{}\begin{matrix}64x+56y=30,4\\2x+3y=1,2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,3\\y=0,2\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Cu}=0,3.64=19,2\left(g\right)\\m_{Fe}=0,2.56=11,2\left(g\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Cu}=63,16\%\\\%m_{Fe}=36,84\%\end{matrix}\right.\)
BTNT Cl:
\(n_{AgCl}=2.n_{Cl2}=1,2\left(mol\right)\)
\(\Rightarrow m_{AgCl}=172,2\left(g\right)\)
Câu 2:
Gọi \(\left\{{}\begin{matrix}n_{Al}:x\left(mol\right)\\n_{Zn}:y\left(mol\right)\end{matrix}\right.\)
\(2Al+6HCl2\rightarrow AlCl_3+3H_2\)
x______________x________3x/2
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
y___________y_________y
\(m_{kl}=27x+65y=3,57\left(1\right)\)
\(m_{muoi}=133,5x+136y=12,09\left(2\right)\)
\(\left(1\right)+\left(2\right)\Rightarrow\left\{{}\begin{matrix}x=0,06\\y=0,03\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,06.27=1,62\left(g\right)\\m_{Zn}=0,03.65=1,95\left(g\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%_{Al}=45,38\%\\\%_{Zn}=54,62\%\end{matrix}\right.\)
Bảo toàn e: \(n_{H2}=0,12\left(mol\right)\Rightarrow V=\frac{32}{12}=2,46\left(l\right)\)
11) Theo đề, ta có: \(n_{MnO_2}=\dfrac{78,3}{87}=0,9\left(mol\right)\)
PTHH: \(MnO_2+4HCl\rightarrow MnCl_2+2H_2O+Cl_2\left(1\right)\)
Số mol: 0,9 mol 3,6 mol 0,9 mol 1,8 mol 0,9 mol
a, Theo phương trình, ta có: \(n_{HCl}=4n_{MnO_2}=4.0,9=3,6\left(mol\right);n_{Cl_2}=n_{MnO_2}=0,9\left(mol\right)\)
\(\Rightarrow m_{HCl}=3,6.36,5=131,4\left(g\right)\)
Mặt khác, C% dung dịch HCl = \(\dfrac{m_{HCl}}{m_{ddHCl}}.100\%\) \(\Leftrightarrow20\%=\dfrac{131,4}{m_{ddHCl}}.100\%\Leftrightarrow m_{ddHCl}=\dfrac{131,4.100}{20}=657\left(g\right)\)(\(m_{ddHCl}\) là khối lượng dung dịch HCl).
\(V_{Cl_2}=0,9.22,4=20,16\left(l\right)\)
b, Theo phương trình, \(n_{MnCl_2}=n_{MnO_2}=0,9\left(mol\right)\)
\(\Rightarrow m_{MnCl_2}=0,9.126=113,4\left(g\right)\)
Mặt khác,
mdung dịch sau phản ứng = \(m_{MnCl_2}+\) mdung dịch HCl - \(m_{Cl_2}\)
= \(78,3+657-\left(0,9.35,5.2\right)\)
= 671,4 (g)
\(\Rightarrow C\%\)dung dịch \(MnCl_2\) = \(\dfrac{113,4}{671,4}.100\%=16,89\%\)
c, Theo (1), \(n_{Cl_2}=n_{MnCl_2}=0,9\left(mol\right)\)
PTHH: \(Fe+\dfrac{3}{2}Cl_2\rightarrow FeCl_3\left(2\right)\)
Số mol: 0,6 \(\rightarrow\) 0,9 \(\rightarrow\) 0,6
Theo (2) \(\Rightarrow n_{FeCl_3}=n_{Fe}=0,6\left(mol\right)\)
\(\Rightarrow m_{FeCl_3}=0.6.162,5=97,5\left(g\right)\)
\(\Rightarrow m\) dung dịch muối thu được = 97,5 + 52,5 =150 (g).
\(\Rightarrow C\%\)dung dịch \(FeCl_3\)= \(\dfrac{97,5}{150}.100\%=65\%\)
số xấu lắm bn coi có lộn số j hơm:<
nAl=0,337 mol á