\(n_{AgCl}=\dfrac{43,05}{143,5}=0,3\left(mol\right)\)

PTHH: 2R + 3Cl₂ → 2RCl₃

PTHH: RCl₃ + 3AgNO₃ → R(NO₃)₃ + 3AgCl

Mol:      0,1                                                       0,3

\(\Rightarrow M_{RCl_3}=\dfrac{16,25}{0,1}=162,5\left(g/mol\right)\)

 \(\Rightarrow M_R=162,5-3.35,5=56\left(g/mol\right)\)

⇒ R là kim loại sắt (Fe)

Chọn đáp án A

Bảo toàn electron:

Chọn đáp án C

2M     +    3 C l 2       →     2 M C l 3

10 , 8 M                                 53 , 4 M + 106 , 5             

⇒ 10 , 8 M   = 53 , 4 M + 106 , 5  → M = 56 (Fe)

Đánh giá 5 sao nhé

\(n_M=\dfrac{7,2}{M_M}\left(mol\right)\)

PTHH: M + Cl₂ --t^o--> MCl₂

          \(\dfrac{7,2}{M_M}\)------------>\(\dfrac{7,2}{M_M}\)

=> \(\dfrac{7,2}{M_M}\left(M_M+71\right)=28,5=>M_M=24\left(Mg\right)\)

giúp với 

$2M + 3Cl_2 \xrightarrow{t^o} 2MCl_3$

Theo PTHH : 

$n_M = n_{MCl_3} \Rightarrow \dfrac{10,8}{M} = \dfrac{53,4}{M + 35,5.3}$

$\Rightarrow M = 27(Al)$
 

PT: \(2M+3Cl_2\underrightarrow{t^o}2MCl_3\)

\(n_M=\dfrac{10,8}{M_M}\left(mol\right)\), \(n_{MCl_3}=\dfrac{53,4}{M_M+35,5.3}\left(mol\right)\)

Theo PT: \(n_M=n_{MCl_3}\Rightarrow\dfrac{10,8}{M_M}=\dfrac{53,4}{M_M+35,5.3}\Rightarrow M_M=27\left(g/mol\right)\)

Vậy: M là Al.