Nhúng một lá sắt [dư] vào dung dịch chứa một trong các chất sau: FeCl3, AlCl3, CuSO4, Pb[NO3]2, H2SO4 đặc nóng. Sau khi phản ứng kết thúc lấy lá sắt ra, có bao nhiêu trường hợp muối sắt[II]?
A. 2.
B. 3.
C. 4.
D. 5.
Đáp án và lời giải
Đáp án:C
Lời giải:
Các phương trình phản ứng: Fe + 2FeCl3
Fe + AlCl3
Fe + CuSO4
Fe + Pb[NO3]2
Các thí nghiệm tạo ra Fe[II] là nhúng lá sắt dư vào các dung dịch FeCl3, CuSO4, Pb[NO3]2, H2SO4 đặc nóng.
Vậy đáp án đúng là C.
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