Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(n_{H_2}=0,9\left(mol\right)\\ Đặt:n_{Zn}=a\left(mol\right);n_{Mg}=b\left(mol\right)\\ PTHH:Zn+2HCl\rightarrow ZnCl_2+H_2\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ \Rightarrow\left\{{}\begin{matrix}65a+24b=40,65\\a+b=0,9\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,4646341463\\b=0,4353658537\end{matrix}\right.\)
Xem lại đề nha em
a, \(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
\(2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)
Ta có: 40nNaOH + 56nKOH = 25,44 (1)
\(n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}+\dfrac{1}{2}n_{KOH}=0,3.0,9=0,27\left(mol\right)\left(2\right)\)
Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}n_{NaOH}=0,3\left(mol\right)\\n_{KOH}=0,24\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{NaOH}=0,3.40=12\left(g\right)\\m_{KOH}=0,24.56=13,44\left(g\right)\end{matrix}\right.\)
b, \(m_{ddH_2SO_4}=300.1,14=342\left(g\right)\)
\(\Rightarrow C\%_{H_2SO_4}=\dfrac{0,27.98}{342}.100\%\approx7,74\%\)
\(a.n_{H_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\\ Đặt:\left\{{}\begin{matrix}n_{Al}=a\left(mol\right)\\n_{Mg}=b\left(mol\right)\end{matrix}\right.\left(a,b>0\right)\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ Mg+H_2SO_4\rightarrow MgSO_4+H_2\\ \rightarrow\left\{{}\begin{matrix}27a+24b=5,1\\1,5a+b=0,25\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,1\\b=0,1\end{matrix}\right.\\ \left\{{}\begin{matrix}\%m_{Al}=\dfrac{27.0,1}{5,1}.100\approx52,941\%\\\%m_{Mg}\approx47,059\%\end{matrix}\right.\)
\(b.m_{ddH_2SO_4}=\dfrac{0,25.98.100}{9,8}=250\left(g\right)\\ m_{ddsau}=m_{Al,Mg}+m_{ddH_2SO_4}-m_{H_2}=5,1+250-0,25.2=254,6\left(g\right)\\ C\%_{ddAl_2\left(SO_4\right)_3}=\dfrac{0,05.342}{254,6}.100\approx6,716\%\\ C\%_{ddMgSO_4}=\dfrac{0,1.120}{254,6}.100\approx4,713\%\)
Bài 1:
\(n_{H_2SO_4}=\dfrac{200.14,7\%}{98}=0,3\left(mol\right)\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}.0,3=0,1\left(mol\right)\\ m_{Al_2\left(SO_4\right)_3}=342.0,1=34,2\left(g\right)\)
Bài 2:
\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{Mg}=n_{H_2}=0,15\left(mol\right)\\ \Rightarrow m_{Mg}=0,15.24=3,6\left(g\right)\\ \%m_{Mg}=\dfrac{3,6}{10}.100=36\%\\ \%m_{Cu}=100\%-36\%=64\%\)
Ta có: \(n_{CuO}=\dfrac{16}{80}=0,2mol\)
PTHH: \(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)
Theo PTHH: \(n_{H2}so_4=^nCuO=0,2mol\)
\(\rightarrow m_{H_2SO_4}=0,2.98=19,6g\)
\(+)^mddH_2SO_4=\dfrac{^mH_2SO_4}{C\%}.100=196g\)
Đến đây thì bn bt lm chx ạ?
Mg + 2HCl → MgCl2 + H2 (1)
Al2O3 + 6HCl → 2AlCl3 + 3H2O (2)
nH2 = 2,8/22,4 = 0,125 mol
Theo tỉ lệ phản ứng (1) => nMg = nH2 = 0,125 mol
<=> mMg = 0,125 .24 = 3 gam và mAl2O3 = 8,1 - 3 =5,1 gam
%mMg = \(\dfrac{3}{8,1}\).100% = 37,03% => %mAl2O3 = 100 - 37,03 = 62,97%
b) nAl2O3 = \(\dfrac{5,1}{102}\)= 0,05 mol
=> nHCl pư = 2nMg + 6nAl2O3 = 0,55 mol
mHCl = 0,55.36,5 = 20,075 gam
=> mdung dịch HCl 18% = \(\dfrac{20,075}{18\%}\)= 111,53 gam
a, \(Zn+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2\)
Bạn bổ sung thêm số liệu của khí thoát ra nhé.