a, PT: \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)

\(C_2H_4+3O_2\underrightarrow{t^o}2CO_2+2H_2O\)

Ta có: \(n_{CH_4}+n_{C_2H_4}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\left(1\right)\)

Theo PT: \(n_{CO_2}=n_{CH_4}+2n_{C_2H_4}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\left(2\right)\)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}n_{CH_4}=0,2\left(mol\right)\\n_{C_2H_4}=0,1\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\%V_{CH_4}=\dfrac{0,2.22,4}{6,72}.100\%\approx66,67\%\\\%V_{C_2H_4}\approx33,33\%\end{matrix}\right.\)

b, Theo PT: \(n_{O_2}=2n_{CH_4}+3n_{C_2H_4}=0,7\left(mol\right)\)

\(\Rightarrow V_{O_2}=0,7.22,4=15,68\left(l\right)\)

\(n_{Mg}=\dfrac{m}{M}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ PTHH:2Mg+O_2\underrightarrow{t^o}2MgO\\ \left(mol\right)-0,2--0,1--0,2\\ V_{O_2}=n.22,4=0,1.22,4=2,24\left(l\right)\)

Câu 33:

nC=3,6/12=0,3(mol)

PTHH: C + O2 -to-> CO2

nO2=nC=0,3(mol)

=>V(O2,đktc)=0,3.22,4=6,72(l)

Vì : V(O2,đktc)=1/5. V(kk)

=>V(kk)=5.V(O2,đktc)= 5.6,72=33,6(l)

=> Chọn C

Câu 34:

nH2=3,36/22,4=0,15(mol)

PTHH: 2Al + 6 HCl -> 2 AlCl3 + 3 H2

Ta có: nAl=2/3. nH2=2/3. 0,15=0,1(mol)

=>mAl=0,1. 27=2,7(g)

=> CHỌN A

33C

Số mol O2= số mol C= 0,3mol

V(o2)= 0,3*22,4=6,72(lit)

V(kk)=5V(o2)=33,6(l)

34A

2Al  + 6HCl-> 2AlCl3+ 3H2

Số mol H2= 0,15mol

=> số mol Al= 0,15*2/3=0,1mol

m(Al)=0,1*27=2,7(g)

Anh có giải rồi á!

Câu 33:

nC=3,6/12=0,3(mol)

PTHH: C + O2 -to-> CO2

nO2=nC=0,3(mol)

=>V(O2,đktc)=0,3.22,4=6,72(l)

Vì : V(O2,đktc)=1/5. V(kk)

=>V(kk)=5.V(O2,đktc)= 5.6,72=33,6(l)

=> Chọn C

Câu 34:

nH2=3,36/22,4=0,15(mol)

PTHH: 2Al + 6 HCl -> 2 AlCl3 + 3 H2

Ta có: nAl=2/3. nH2=2/3. 0,15=0,1(mol)

=>mAl=0,1. 27=2,7(g)

=> CHỌN A

33: C

34: A

\(a,CH_4+2O_2\rightarrow\left(t^o\right)CO_2+2H_2O\)

 Vì n và V tỉ lệ thuận với nhau. Nên ta có:

\(V_{O_2}=2.V_{CH_4}=2.2,768=5,536\left(l\right)\)

\(b,V_{kk}=\dfrac{100}{21}.V_{O_2}=\dfrac{100}{21}.5,536=\dfrac{2768}{105}\left(l\right)\)

\(C_2H_4+3O_2\underrightarrow{t^o}2CO_2+2H_2O\)

\(\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

\(nO_2=3.0,25=0,75\left(mol\right)\)

\(VO_2=0,75.22,4=16,8\left(l\right)\)

\(nCO_2=2.0,25=0,5\left(mol\right)\)

\(VCO_2=0,5.224=11,2\left(l\right)\)

\(n_{C_2H_5OH}=\dfrac{23}{46}=0,5\left(mol\right)\\a, PTHH:C_2H_5OH+3O_2\rightarrow\left(t^o\right)2CO_2+3H_2O\\ b,n_{O_2}=3.0,5=1,5\left(mol\right)\\ V_{O_2\left(đktc\right)}=22,4.1,5=33,6\left(l\right)\\ c,V_{C_2H_5OH}=46\%.100=46\left(ml\right)\\ C_2H_5OH+Na\rightarrow C_2H_5ONa+\dfrac{1}{2}H_2\\ n_{C_2H_5OH}=\dfrac{0,8.46}{46}=0,8\left(mol\right)\\ n_{H_2}=\dfrac{0,8}{2}=0,4\left(mol\right)\Rightarrow V_{H_2\left(đktc\right)}=0,4.22,4=8,96\left(l\right)\)