Bài 1:

a) \(V_{khí}=\left(0,2+0,5+0,35\right)\cdot22,4=23,52\left(l\right)\)

b) \(m_{khí}=0,2\cdot64+0,5\cdot28+0,35\cdot28=36,6\left(g\right)\)

Bài 2:

Sửa đề: Tỉ lệ \(Mg:C:O=2:1:4\)

Ta có: \(n_{Mg}:n_C:n_O=\dfrac{2}{24}:\dfrac{1}{12}:\dfrac{4}{16}=1:1:3\)

\(\Rightarrow\) CTHH là MgCO₃

1,a,Gọi \(n_{Al}=a\left(mol\right)\rightarrow n_{Mg}=0,5a\left(mol\right)\)

\(\rightarrow27a+24.0,5b=7,8\\ \Leftrightarrow a=0,2\left(mol\right)\\ \rightarrow\left\{{}\begin{matrix}n_{Al}=0,2\left(mol\right)\\n_{Mg}=0,1\left(mol\right)\end{matrix}\right.\)

b, \(\rightarrow\left\{{}\begin{matrix}m_{Al}=0,2.27=5,4\left(g\right)\\m_{Mg}=0,1.24=2,4\left(g\right)\end{matrix}\right.\)

2, \(n_{O_2}=\dfrac{0,16}{32}=0,005\left(mol\right)\)

PTHH: 2HgO --t^o--> 2Hg + O₂

                                 0,01<- 0,05

\(\rightarrow m_{Hg}=0,01.201=2,01\left(g\right)\)

a) \(\overline{M}_A=5,875.2=11,75\left(g/mol\right)\)

b) Gọi số mol N₂, H₂ là a, b (mol)

\(\overline{M}_A=\dfrac{28a+2b}{a+b}=11,75\left(g/mol\right)\)

=> 16,25a = 9,75b 

=> a = 0,6b 

\(\left\{{}\begin{matrix}\%n_{N_2}=\dfrac{a}{a+b}.100\%=\dfrac{0,6b}{0,6b+b}.100\%=37,5\%\\\%n_{H_2}=\dfrac{b}{a+b}.100\%=\dfrac{b}{0,6b+b}.100\%=62,5\%\end{matrix}\right.\)

c) 

1 mol hỗn hợp A chứa \(\left\{{}\begin{matrix}n_{N_2}=\dfrac{1.37,5}{100}=0,375\left(mol\right)\\n_{H_2}=\dfrac{1.62,5}{100}=0,625\left(mol\right)\end{matrix}\right.\)

\(\overline{M}_B=\dfrac{0,375.28+0,625.2+17x}{1+x}=6,4.2=12,8\left(g/mol\right)\)

=> x = 0,25 (mol)

\(a.\)

\(n_{hh}=0.2+0.15+0.1=0.45\left(mol\right)\)

\(V_X=0.45\cdot22.4=10.08\left(l\right)\)

\(b.\)

\(m_X=0.2\cdot28+0.15\cdot71+0.1\cdot32=19.45\left(g\right)\)

\(c.\)

\(\overline{M}_X=\dfrac{19.45}{0.45}=43.22\left(g\text{/}mol\right)\)

\(d.\)

\(d_{X\text{/}kk}=\dfrac{43.22}{29}=1.4\)

Nặng hơn không khí 1.4 lần