$M_A = 1,517.29 = 44(đvC)$

$M_B = 1,0625.M_{O_2} = 1,0625.32 = 349(đvC)$

a.

\(d_{A\text{/}O_2}=1.375\) \(\Rightarrow M_A=1.375\cdot32=44\left(g\text{/}mol\right)\)

b.

\(d_{B\text{/}kk}=0.586\) \(\Rightarrow M_B=0.586\cdot29=17\left(g\text{/}mol\right)\)

Ta có: \(d_{B/O_2}=\dfrac{M_B}{M_{O_2}}=0,25\Rightarrow M_B=0,25.32=8\left(g/mol\right)\)

\(d_{A/B}=\dfrac{M_A}{M_B}=2,5\Rightarrow M_A=2,5.M_B=20\left(g/mol\right)\)

\(d_{\dfrac{B}{O_2}}=0,5\\ \Leftrightarrow\dfrac{M_B}{M_{O_2}}=0,5\\ \Rightarrow M_B=M_{O_2}.0,5=32.0,5=16\left(\dfrac{g}{mol}\right)\\ d_{\dfrac{A}{B}}=2,125\\ \Leftrightarrow\dfrac{M_A}{M_B}=2,125\\ \Rightarrow M_A=2,125.M_B=2,125.16=34\left(\dfrac{g}{mol}\right)\)

Em coi xem có chỗ nào không hiểu hỏi lại nha! 

d_A/O2 =M_A/32 =0,5

M_A= 0,5.32 = 16

d_B/A= 2,125

M_B = 2,125.16 = 34

\(d_{B/O_2}=\dfrac{M_B}{M_{O_2}}=\dfrac{M_B}{32}=0,5=>M_B=0,5.32=16\)

\(d_{A/B}=\dfrac{M_A}{M_B}=\dfrac{M_A}{M_B}=\dfrac{M_A}{16}=2,125=>M_A=2,125.16=34\)

Chúc bạn học tốt

Khối lượng mol của những khí cho:

a) dX/O2 =  = 1,375 ⇒ MX = 1,375 x 32 = 44 g/mol;

    dY/O2 =  = 0,0625 ⇒ MY = 0,0625 x 32 = 2 g/mol.

b) dX/kk =  = 2,207 ⇒ MX = 29 x 2,207 = 64 g/mol;

    dY/kk =  = 1,172 ⇒ MY = 29 x 1,172 = 34 g/mol.

\(M_A=2.16=32g\\ M_B=2.32=64g\)