Ta có: \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)

PT: \(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)

Theo PT: \(n_{H_2SO_4}=n_{MgSO_4}=n_{H_2}=m_{Mg}=0,2\left(mol\right)\)

a, \(m_{MgSO_4}=0,2.120=24\left(g\right)\)

b, \(V_{H_2}=0,2.24,79=4,958\left(l\right)\)

c, Bạn bổ sung đề phần này nhé.

\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ Mg+H_2SO_4\rightarrow MgSO_4+H_2\\ n_{MgSO_4}=n_{H_2}=n_{H_2SO_4}=n_{Mg}=0,2\left(mol\right)\\ a,m_{MgSO_4}=120.0,2=24\left(g\right)\\ b,V_{H_2\left(đkc\right)}=24,79.0,2=4,958\left(l\right)\\ c,Oxide:A_2O_x\left(x:hoá.trị.A\right)\\ A_2O_x+xH_2SO_4\rightarrow A_2\left(SO_4\right)_x+xH_2O\\ n_{Oxide}=\dfrac{\dfrac{3}{4}.0,2.1}{x}=\dfrac{0,15}{x}\left(mol\right)\\ M_{A_2O_x}=\dfrac{8}{\dfrac{0,15}{x}}=\dfrac{160}{3}x\)

Xét x=1;x=2;x=3;x=8/3 thấy x=3 (TM) khi đó KLR oxide là 160g/mol 

\(M_{M_2O_3}=2M_M+3.16=160\left(\dfrac{g}{mol}\right)\\ \Rightarrow M_M=\dfrac{160-48}{2}=56\left(\dfrac{g}{mol}\right)\)

Nên: M là sắt (Fe=56)

Oxide CTHH: Fe₂O₃

- Potassium sulfate: K₂SO₄

- Sodium hydrogensulfate: NaHSO₄

- Sodium hydrogencarbonate: NaHCO₃

- Sodium chloride: NaCl

- Sodium nitrate: NaNO₃

- Calcium hydrogenphosphate: CaHPO4

- Magnesium sulfate: MgSO₄

- Copper (II) sulfate: CuSO₄

câu 5

Mg+H2SO4->MgSO4+H2

0,35----------------0,35---0,35

n Mg=0,35 mol

=>VH2=0,35.22,4=7,84l

=>m MgSO4=0,35.120=43g

b)H2+CuO-to>H2O+Cu

0,35----0,35--------------0,35

=>m CuO=0,35.80=28g

=>m Cu=0,35.64=22,4g

Câu 5

`a)n_{Mg} = {8,4}/{24} = 0,35(mol)`

`PTHH : Mg + H_2SO_4 -> MgSO_4 + H_2`

`n_{H_2} = n_{Mg} = 0,35(mol)`

`-> V_{H_2} = 0,35.22,4 = 7,84(gam)`

`n_{MgSO_4} = n_{Mg} = 0,35(mol)`

`-> m_{MgSO_4} = 0,35.120 = 42(gam)`

`b)H_2 + CuO ->^{t^o} Cu + H_2O`

`n_{CuO} = n_{H_2} = 0,35(mol)`

`-> m_{CuO} = 0,35.80 = 28(gam)`

`n_{Cu} = n_{H_2} = 0,35(mol)`

`-> m_{Cu} = 0,35.64 = 22,4(gam)`

1) Xuất hiện kết tủa trắng

\(BaCl_2+2AgNO_3\rightarrow Ba\left(NO_3\right)_2+2AgCl\downarrow\)

2) Xuất hiện kết tủa trắng

\(MgSO_4+2KOH\rightarrow Mg\left(OH\right)_2\downarrow+K_2SO_4\)

giúp mình đi m.n

Ta có: \(n_{Al}=\dfrac{12,15}{27}=0,45\left(mol\right)\)

\(n_{CuSO_4}=\dfrac{54}{160}=0,3375\left(mol\right)\)

PT: \(2Al+3CuSO_4\rightarrow Al_2\left(SO_4\right)_3+3Cu\)

Xét tỉ lệ: \(\dfrac{0,45}{2}>\dfrac{0,3375}{3}\), ta được Al dư.

Theo PT: \(n_{Al\left(pư\right)}=\dfrac{2}{3}n_{CuSO_4}=0,225\left(mol\right)\)

\(\Rightarrow n_{Al\left(dư\right)}=0,225\left(mol\right)\Rightarrow m_{Al\left(dư\right)}=0,225.27=6,075\left(g\right)\)

Theo PT: \(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{CuSO_4}=0,1125\left(mol\right)\)

\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=0,1125.342=38,475\left(g\right)\)

\(n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\)

PTHH :

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\uparrow\)

0,1        0,1             0,1             0,1 

\(a,m_{MgSO_4}=0,1.120=12\left(g\right)\)

\(b,V_{H_2}=0,1.22,4=2,24\left(l\right)\)

\(c,m_{ddH_2SO_4}=\dfrac{0,1.98.100}{10}=98\left(g\right)\)