\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(2Al\left(OH\right)_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+6H_2O\)

\(CuO+2HNO_3\rightarrow Cu\left(NO_3\right)_2+H_2O\)

 1. Fe + 2HCl → FeCl2 + H2

2Al + 3H2SO4 → Al2(SO4)3 + 3H2

CuO + H2SO4 → CuSO4 + H2O

2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O

CuO + 2HNO3 → Cu(NO3)2 + H2O

a)C%KCl=20/500×100=4%

b)C%NaCl=15/(15+45)×100=25%

Bn ko bt lm thì cũng đừng dùng chat gtp 

a, C%CuSO4=8/(192+8)×100=4%

b, C%Al2(SO4)3=32/(32+368)×100=8%

\(\dfrac{x\sqrt{x}+1}{x-1}-\dfrac{x-1}{\sqrt{x}+1}\\ =\dfrac{x\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}-\dfrac{x-1}{\sqrt{x}+1}\\ =\dfrac{x\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}-\dfrac{\left(x-1\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\\ =\dfrac{x\sqrt{x}+1-\left(x\sqrt{x}-x-\sqrt{x}+1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\\ =\dfrac{x\sqrt{x}+1-x\sqrt{x}+x+\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\\ =\dfrac{x+\sqrt{x}}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\\ =\dfrac{\sqrt{x}\left(\sqrt{x}+1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\\\)

\(=\dfrac{\sqrt{x}}{\sqrt{x}-1}\)

Đăng đúng môn nhe cậu 

ạ máy em hơi lag nên v á 

Gọi CTHH của X là: \(\left(Ca_xC_yO_z\right)_n\)

Ta có: \(x:y:z=\dfrac{40}{40}:\dfrac{12}{12}:\dfrac{48}{16}=1:1:3\) (Tử số là % thành phần)

Suy ra, CTĐG của X là: \(\left(CaCO_3\right)_n\)

Mà \(M_X=100\left(g\right)\Leftrightarrow\left(40+12+16.3\right).n=100\Leftrightarrow n=1\)

\(\Rightarrow\) CTHH của X là CaCO₃

cảm ơn b

\(3Cu+8H^++2NO_3^-\rightarrow2NO+4H_2O+3Cu^{2+}\)

3z---->8z----->2z

\(2H^++O^{2-}\rightarrow H_2O\)

2y<---y

\(Cu+2Fe^{3+}\rightarrow Cu^{2+}+2Fe^{2+}\)

x---->2x

+ Hỗn hợp ban đầu: \(\left\{{}\begin{matrix}Fe^{3+}:2x\\O:y\\Cu:x+3z\\NO_3:2z\end{matrix}\right.\)

\(\Sigma n_{Fe}=2x=\dfrac{2z}{3}+\dfrac{2y}{3}\Leftrightarrow3x=y+z\left(1\right)\)

\(\Sigma n_{H^+\left(H_2SO_4\right)}=2y+8z=0,42.2=0,84\left(2\right)\)

\(m=37,06=56.2x+16y+64\left(x+3z\right)+62.2z\left(3\right)\)

Từ (1), (2), (3), giải được \(\left\{{}\begin{matrix}x=0,065\\y=0,12\\z=0,075\end{matrix}\right.\)

Số mol mỗi chất trong X: \(\left\{{}\begin{matrix}n_{Fe\left(NO_3\right)_3}=\dfrac{2z}{3}=\dfrac{2.0,075}{3}=0,05\left(mol\right)\\n_{Fe_2O_3}=\dfrac{y}{3}=\dfrac{0,12}{3}=0,04\left(mol\right)\\n_{Cu}=x+3z=0,065+3.0,075=0,29\left(mol\right)\end{matrix}\right.\)