C% dung dịch sau cùng thì phải có cả dư và tạo thành chứ.

\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ m_{HCl}=\dfrac{100.36,5}{100}=36,5\left(g\right)\\ n_{HCl}=\dfrac{36,5}{36,5}=1\left(mol\right)\\ Mg+2HCl\xrightarrow[]{}MgCl_2+H_2\\ \dfrac{0,2}{1}< \dfrac{1}{2}\Rightarrow HCl.dư\\ n_{Mg}=n_{MgCl_2}=n_{H_2}=0,2mol\\ m_{MgCl_2}=0,2.95=19\left(g\right)\\ m_{H_2}=0,2.2=0,4\left(g\right)\\ m_{ddMgCl_2}=4,8+100-0,4=104,4\left(g\right)\\ C_{\%MgCl_2}=\dfrac{19}{104,4}\cdot100\approx18,19\%\)

\(m_{HCl}=\dfrac{100.36,5}{100}=36,5\left(g\right)\\ n_{HCl}=\dfrac{36,5}{36,5}=1\left(mol\right)\\ n_{CaCO_3}=\dfrac{10}{100}=0,1\left(mol\right)\\ CaCO_3+2HCl\xrightarrow[]{}CaCl_2+CO_2+H_2O\\ \dfrac{0,1}{1}< \dfrac{1}{2}\Rightarrow HCl.dư\\ n_{CaCO_3}=n_{CaCl_2}=n_{CO_2}=0,1mol\\ m_{CaCl_2}=0,1.111=11,1\left(g\right)\\m_{CO_2}=0,1.44=4,4\left(g\right)\\ m_{ddCaCl_2}=10+100-4,4=105,6\left(g\right)\\ C_{\%CaCl_2}=\dfrac{11,1}{105,6}\cdot100\%\approx10,5\%\)

\(n_{Fe}=a;n_{Cu}=b\\ 56a+64b=9,2\left(I\right)\\ BTe^{^{ }-}:3a+2b=2n_{SO_2}\left(II\right)\\ n_{H_2SO_4pư}=n_{SO_2}+1,5a+b\\ n_{H_2SO_4sau}=\dfrac{50.0,98}{98}-n_{SO_2}-1,5a-b=0,5-n_{SO_2}-1,5a-b\\ m_{ddsau}=9,2+50-64n_{SO_2}=59,2-64n_{SO_2}\\ \Rightarrow:\dfrac{98\left(0,5-n_{SO_2}-1,5a-b\right)}{59,2-64n_{SO_2}}=\dfrac{30,625}{100}\left(III\right)\\ \Rightarrow a=0,05;b=0,1;n_{SO_2}=0,175mol\\ V=0,175.22,4=3,92L\\ \%m_{Fe}=\dfrac{0,05.56}{9,2}.100\%=30,43\%\\ \%m_{Cu}=69,57\%\)

Lười gõ quá nên mình không làm chi tiết, không hiểu cái nào thì hỏi:v

Đặt CTHH của oxit sắt là \(Fe_xO_y\)

\(m_{giảm}=3,52\Rightarrow m_{CO_2}=3,52\left(g\right)\Rightarrow n_{CO_2}=\dfrac{3,52}{44}=0,08\left(mol\right)\)

\(\Rightarrow\dfrac{0,08}{y}=n_{Fe_xO_y}=\dfrac{5,76}{56x+16y}\)

\(\Rightarrow x:y=1:1\)

\(\Rightarrow CT:FeO\)

\(n_A=\dfrac{4,48}{22,4}=0,2\left(mol\right)\Rightarrow n_{CO}=0,2-0,08=0,12\left(mol\right)\)

\(\Rightarrow m_{CO}+m_{CO_2}=44.0,08+0,12.28=6,88\)

\(\Rightarrow d_{A/H_2}=\dfrac{6,88}{2}=3,44\)

Nói đơn giản là theo phương trình:

\(Fe_xO_y+yCO\underrightarrow{t^o}xFe+yCO_2\)

  \(\dfrac{0,08}{y}\) <-------------------- 0,08

Nói ngắn gọn là theo BT O :v

Sửa đề: 

Cho 1,6g CuO tác dụng với 200g dụng dịch h2so4 a.Tính khối lượng h2so4 phản ứng b.tính nồng độ % của h2so4 c.tính khối lượng muối thu đc

Giải

\(a.n_{CuO}=\dfrac{1,6}{80}=0,02\left(mol\right)\\ CuO+H_2SO_4\xrightarrow[]{}CuSO_4+H_2\\ n_{H_2SO_4}=n_{CuSO_4}=n_{CuO}=0,02mol\\ m_{H_2SO_4}=0,02.98=1,96\left(g\right)\\ b.m_{ddH_2SO_4}=1,6+200=201,6\left(g\right)\\ C_{\%H_2SO_4}=\dfrac{1,96}{201,6}\cdot100\%\approx0,97\%\\ c.m_{CuSO_4}=0,02.160=3,2\left(g\right)\)

Cuộc là sao ?

CuO hả?

\(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\\ PTHH:Na_2O+H_2O\rightarrow2NaOH\\ n_{NaOH}=2.0,25=0,5\left(mol\right)\\ a,C_{MddNaOH}=\dfrac{0,5}{0,5}=1\left(M\right)\\ b,2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\\ n_{H_2SO_4}=n_{Na_2SO_4}=\dfrac{0,5}{2}=0,25\left(mol\right)\\ m_{H_2SO_4}=0,25.98=24,5\left(g\right)\\ m_{ddH_2SO_4}=\dfrac{24,5.100}{20}=122,5\left(g\right)\\ V_{ddH_2SO_4}=\dfrac{122,5}{1,14}\approx107,456\left(ml\right)\\ c,V_{ddsau}=V_{ddNaOH}+V_{ddH_2SO_4}\approx0,5+0,107456=0,607456\left(l\right)\\C_{MddNa_2SO_4}\approx\dfrac{ 0,25}{0,607456}\approx0,411552\left(M\right)\)

\(n_{H_2SO_4}=\dfrac{98.5\%}{98}=0,05\left(mol\right)\\ PTHH:CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ n_{CuSO_4}=n_{CuO}=n_{H_2SO_4}=0,05\left(mol\right)\\ a,m_{CuO}=0,05.80=4\left(g\right)\\ b,m_{CuSO_4}=0,05.160=8\left(g\right)\\ m_{ddCuSO_4}=98+4=102\left(g\right)\\ C\%_{ddCuSO_4}=\dfrac{8}{102}.100\approx7,843\%\)

\(n_{HCl}=\dfrac{30.7,3\%}{36,5}=0,06\left(mol\right)\\ PTHH:KOH+HCl\rightarrow KCl+H_2O\\ n_{KOH}=n_{HCl}=0,06\left(mol\right)\\ m_{KOH}=0,06.56=3,36\left(g\right)\\ m_{ddKOH}=\dfrac{3,36.100}{5}=67,2\left(g\right)\\ V_{ddKOH}=\dfrac{67,2}{1,082}\approx\text{62,1072089(ml)}\)

\(a.Mg+2HCl->MgCl_2+H_2\\ MgO+2HCl->MgCl_2+H_2O\\ b.n_{H_2}=\dfrac{2,24}{22,4}=n_{Mg}=0,1mol\\ \%m_{Mg}=\dfrac{0,1.24}{6}=40\%;\%m_{MgO}=60\%\\ n_{MgO}=\dfrac{0,6.6}{40}=0,09\left(mol\right)\\ n_{MgCl_2}=0,1+0,09=0,19\left(mol\right)\\ n_{HCl}=0,19.2=0,38\left(mol\right)\\ V_{ddHCl}=\dfrac{0,38.36,5}{0,2.1,1}=63,0\left(mL\right)\\ C_{M\left(MgCl_2\right)}=\dfrac{0,19}{0,063}=3,0\left(M\right)\)