1.\(a.CTHH:Fe_2\left(SO_4\right)_x\\ Tacó:56.2+\left(32+16.4\right).x=400\\ \Rightarrow x=3\\ VậyCTHH:Fe_2\left(SO_4\right)_3\\ b.CTHH:Fe_xO_3\\ Tacó:56.x+16.3=160\\ \Rightarrow x=2\\ VậyCTHH:Fe_2O_3\)

2. \(M_{Cu}=64\left(g/mol\right)\\ M_{H_2O}=2+16=18\left(g/mol\right)\\ M_{CO_2}=14+16.2=44\left(g/mol\right)\\ M_{CuO}=64+16=80\left(g/mol\right)\\ M_{HNO_3}=1+14+16.3=63\left(g/mol\right)\\ M_{CuSO_4}=64+32+16.4=160\left(g/mol\right)\\ M_{Al_2\left(SO_4\right)_3}=27.2+\left(32+16.4\right).3=342\left(g/mol\right)\)

\(M_{Fe_2\left(SO_4\right)_x}=56\cdot2+96x=400\left(đvc\right)\\ \Leftrightarrow x=3\)

\(\Rightarrow Fe_2\left(SO_4\right)_3\)

\(M_{Fe_xO_3}=56x+16\cdot3=160\left(đvc\right)\\ \Leftrightarrow x=2\)

\(\Rightarrow Fe_2O_3\)

\(M_{K_xSO_4}=39x+32+64=174\left(đvc\right)\Leftrightarrow x=2\)

\(\Rightarrow K_2SO_4\)

a) \(Fe_2\left(SO_4\right)_x\)

\(PTK_{h/c}=2.NTK_{Fe}+x.\left(PTK_{SO_4}\right)=400\)

\(\Rightarrow2.56+x.96=400\)

\(\Rightarrow96x=400-2.56=288\)

\(\Rightarrow x=288:96=3\)

b) \(PTK_{h/c}=x.NTK_{Fe}+3.NTK_O=160\)

\(\Rightarrow x.56+3.16=160\)

\(\Rightarrow56x=160-3.16=112\)

\(\Rightarrow x=2\)

c) \(PTK_{h/c}=x.NTK_K+NTK_S+4.NTK_O=174\)

\(\Rightarrow x.39+32+4.16=174\)

\(\Rightarrow39x=174-32-4.16=78\)

\(\Rightarrow x=2\)

1. Ta có: 56 x 2 + ( 32 + 16 x 4 )x = 400

=> x = 3

=> CTHH: Fe₂(SO4)₃

2. Cách giải tương tự 1

=> CTHH: Al₂(SO4)₃

3. Cách giải tương tự 1

=> CTHH: K₂SO₄

cặc

1. x = 3

Fe(III)

2. R: Bari. Kí hiệu: Ba.

a, fe2o3

b, al2(so4)3

CTHH: K2(SO4)x

=> 39 + 96x = 174

=> x = 1 

CTHH: K2SO4

CTHH: Cax(PO4)2

=> 40x + 95 . 2 = 310

=> x = 3

CTHH: Ca3(PO4)2

CTHH: Cu(NO3)x

=> 64 + 78x = 188

=> x = 2

CTHH: Cu(NO3)2

CTHH của hợp chất: \(XY_3\)

Ta có: \(\dfrac{m_X}{m_Y}=\dfrac{X}{3Y}=\dfrac{2}{3}\left(1\right)\)

Mặt khác: X+ 3Y=80 (2)

Từ (1), (2) => X=32 (Lưu huỳnh- S), Y=16 (Oxi- O)

=> CTHH của hợp chất: \(SO_3\)

a, Ta có : \(M_{Fe_xO_3}=160\)g

\(\Leftrightarrow56x+16.3=160\Leftrightarrow x=2\)

=> CTHH là Fe₂O₃