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

\(n_{O_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

PTHH: 4Al + 3O₂ --t^o--> 2Al₂O₃

Xét tỉ lệ: \(\dfrac{0,45}{4}>\dfrac{0,3}{3}\)=> Al dư, O₂ hết

PTHH: 4Al + 3O₂ --t^o--> 2Al₂O₃

            0,4<--0,3-------->0,2

=> \(m_{Al\left(dư\right)}=\left(0,45-0,4\right).27=1,35\left(g\right)\)

b) \(m_{Al_2O_3}=0,2.102=20,4\left(g\right)\)

Khối lượng chất rắn trong bình tăng là khối lượng khí clo phản ứng

\(n_{Cl_2}=\dfrac{4,26}{71}=0,06\left(mol\right)\\ PTHH:2Al+3Cl_2\underrightarrow{t^o}2AlCl_3\)

Theo pthh, ta có: \(n_{Al}=\dfrac{2}{3}n_{Cl_2}=\dfrac{2}{3}.0,06=0,04\left(mol\right)\)

\(m_{Al}=0,04.27=1,08\left(g\right)\)

2Al + 3Cl2 => 2AlCl3

mCl pư = m chất rắn tăng = 4,26 (g)

=> nCl= 0,12

=> nAl pư = 1/3 nCl = 0,04 => mAl pư= 1,08 (g)

Bài 1:

\(a,2Cu+O_2\underrightarrow{t^o}2CuO\)

b, \(n_{O_2}=\dfrac{1,12}{32}=0,035mol\)

\(n_{Cu}=\dfrac{6,4}{64}=0,1mol\)

\(\dfrac{0,1}{2}>\dfrac{0,035}{1}\) => Cu dư, O₂ đủ

\(n_{Cu}\left(dư\right)=0,1-0,07=0,039\left(mol\right)\)

c, \(m_{CuO}=0,07.80=5,6g\)

Bài 2:

\(n_{Al}=\dfrac{13,5}{27}=0,5mol\)

\(n_{O_2}=\dfrac{6,67}{32}=0,21\left(mol\right)\)

\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

\(\dfrac{0,5}{4}>\dfrac{0,21}{3}\) => Al dư, O₂ đủ

\(n_{Al_2O_3}=\dfrac{2}{3}.0,21=0,14\left(mol\right)\)

\(m_{Al_2O_3}=0,14.102=14,28g\)

Chưa làm câu ni à

Mới làm được khi chiều xong

\(n_P=\dfrac{3,1}{31}=0,1\left(mol\right)\\ n_{O_2}=\dfrac{3,2}{32}=0,1\left(mol\right)\\ pthh:4P+5O_2\underrightarrow{t^o}2P_2O_5\\ LTL:\dfrac{0,1}{4}>\dfrac{0,1}{5}\) 
=> P dư 
\(n_{P\left(p\text{ư}\right)}=\dfrac{4}{5}n_{O_2}=0,08\left(mol\right)\\ m_{P\left(d\right)}=\left(0,1-0,08\right).31=0,62\left(g\right)\)

\(n_P=\dfrac{3,1}{31}=0,1\left(mol\right)\\ n_{O_2}=\dfrac{3,2}{32}=0,1\left(mol\right)\)

PTHH: \(4P+5O_2\xrightarrow[]{t^o}2P_2O_5\)

bđ      0,1       0,1

pư     0,08     0,1

spư    0,02     0         

=> P dư

\(m_{P\left(dư\right)}=0,02.31=0,62\left(g\right)\)

a)

\(n_{Al} = \dfrac{12,15}{27} = 0,45(mol)\\ n_{O_2} = \dfrac{6,72}{22,4} = 0,3(mol)\\ 4Al + 3O_2 \xrightarrow{t^o} 2Al_2O_3\\ \dfrac{n_{Al}}{4} = 0,1125 < \dfrac{n_{O_2}}{3} = 0,1\)

Do đó, Al dư.

\(n_{Al\ pư} = \dfrac{4}{3}n_{O_2} = 0,4(mol)\\ m_{Al\ dư} = (0,45-0,4).27 =1,35(gam)\)

b) Nhôm oxit được tạo thành.

\(n_{Al_2O_3} = \dfrac{2}{3}n_{O_2} = 0,2(mol)\\ \Rightarrow m_{Al_2O_3} = 0,2.102 = 20,4(gam)\)

\(n_{Al}=\dfrac{m}{M}=0,45\left(mol\right)\)

\(n_{O_2}=\dfrac{V}{22,4}=0,3\left(mol\right)\)

a, \(PTHH:4Al+3O_2\rightarrow2Al_2O_3\)

=> Sau phản ứng O2 hết, Al dư ( dư 0,05 mol )

=> \(m_{Aldu}=n.M=1,35\left(g\right)\)

b, Chất được tạo thành là Al₂O₃ .

Theo PTHH : \(n_{Al_2O_3}=0,2\left(mol\right)\)

\(\Rightarrow m_{Al_2O_3}=n.M=20,4\left(g\right)\)

Vậy ...

\(2Al+3Cl_2\rightarrow\left(t^o\right)2AlCl_3\\ m_{tăng}=m_{Cl_2}\Rightarrow n_{Cl_2}=\dfrac{14,2}{71}=0,2\left(mol\right)\\ \Rightarrow n_{Al}=\dfrac{2}{3}.0,2=\dfrac{2}{15}\left(mol\right)\\ Vậy:m_{Al}=\dfrac{2}{15}.27=3,6\left(g\right)\)

\(n_{Al}=\dfrac{m}{M}=\dfrac{5,4}{27}=0,2\left(mol\right)\\ n_{O_2}=\dfrac{m}{M}=\dfrac{12,8}{32}=0,4\left(mol\right)\)

\(PTHH:4Al+3O_2-^{t^o}>2Al_2O_3\)

tỉ lệ:            4  :  3     :       2

n(mol)       0,2   0,4

m(mol p/u) 0,2-->0,15---->0,1

\(\dfrac{n_{Al}}{4}< \dfrac{n_{O_2}}{3}\left(\dfrac{0,2}{4}< \dfrac{0,4}{3}\right)\)

`=>` `Al` hết , `O_2` dư

`=>` tính theo `Al`

\(n_{O_2\left(dư\right)}=0,4-0,15=0,25\left(mol\right)\\ m_{O_2\left(dư\right)}=n\cdot M=0,25\cdot32=8\left(g\right)\\ m_{Al_2O_3}=n\cdot M=0,1\cdot\left(27\cdot2+16\cdot3\right)=10,2\left(g\right)\)

Giúp ik