Sus Thi Chảnh

2 năm trước

Cho 30g hỗn hợp 2 Kim loại sắt và đồng tác dụng với dung dịch hcl dư sau khi phản ứng song thu được chất rắn a và 6,72 lít khí ở điều kiện tiêu chuẩn Biết phương trình phản ứng hóa học xảy ra Tính thành phần phần trăm theo khối lượng của hỗn hợp ban đầu

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nguyentransondhy

2 năm trước

Đáp án:

%mFe=56%; %mCu=44%

Giải thích các bước giải:

Cho hỗn hợp trên vào dung dịch HCl chỉ có Fe phản ứng

Fe + 2HCl -> FeCl2 + H2

Ta có: nH2=6,72/22,4=0,3 mol=nFe

-> mFe=0,3.56=16,8 gam

->%mFe=16,8/30=56% -> %mCu=100%-%mFe=44%

tridep

2 năm trước

a) Fe + 2HCl → FeCl2 + H2↑

$n_{H_{2}}$ = $\frac{6, 72}{22, 4}$ =0,3 mol

Theo PTHH: $n_{F e}$ = $n_{H_{2}}$ = 0,3 mol

→ mFe = 0,3 . 56 = 16,8 gam

$\begin{aligned} % m_{F e} = \frac{16, 8}{30} .100 % = 56 % \\ \to % m_{C u} = 100 % - 56 % = 44 % \end{aligned}$

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