$\text{Đáp án + giải thích các bước giải :}$

$a)$

$Gọi$ $n_{Al}$ $=$ $x$ $(mol)$

$Vì$ $\frac{n_{Al}}{n_{Zn}}$ $=$ $\frac{6}{5}$ 

$⇒$ $n_{Zn}$ $=$ $\frac{5}{6}n_{Al}$ $=$ $\frac{5}{6}x$ $(mol)$

$⇒$ $27$ $.$ $x$ $+$ $\frac{5}{6}x$ $.$ $65$ $=$ $9,74$

$⇒$ $27x$ $+$ $\frac{325}{6}x$ $=$ $9,74$

$⇒$ $x$ $=$ $0,12$

$⇒$ $n_{Al}$ $=$ $0,12$ $(mol)$

$⇒$ $n_{Zn}$ $=$ $\frac{5}{6}$ $×$ $0,12$ $=$ $0,1$ $(mol)$

$b)$

$\%_{Al}$ $=$ $\frac{m_{Al}}{m_X}$ $×$ $100\%$ $=$ $\frac{0,12×27}{9,74}$ $×$ $100\%$ $≈$ $33,265\%$

$\%_{Al}$ $=$ $100\%$ $-$ $33,265%$ $≈$ $66,735\%$

$\text{Chúc bn hk tốt !! :))))}$

 `a)`

Đặt `n_{Zn} = 5x(mol) → n_{Al} = 6x(mol)`

`m = 27.  6x + 65.  5x = 9,74(g)`

`→ x = 0,02(mol)`

`n_{Al} = 6.  0,02 = 0,12(mol)`

`n_{Zn} = 5 . 0,02 = 0,1(mol)`

`b)`

`%m_{Al} = {0,12.27}/{9,74} .100 = 33,26%`

`%m_{Zn} = 100 - 33,26 =66,74%`