Đề thi chọn HS Giỏi

Trường THCS Trung Thành

Bài kiểm tra chọn học sinh giỏi cấp trường
Môn Hoá hoc. Thời gian làm bài:


Câu 1: Hoàn thành các phương trình hoá học sau:
a. FeO4 + Al Fe + Al2O3
b. Cu + HNO3 Cu(NO3)2 + H2O + NO
c. KMnO4 + HCl KCl + MnCl2 + Cl2 + H2O
d. AlxOy + HCl ? + H2O
Câu 2: Hoàn thành sơ đồ biến hoá sau:
A + X,t0 +B +E
A + Y,t0 Fe D C
A + Z,t0
Biết rằng: A + HCl D + C + H2O
Câu 3: Có 4 lọ mất nhãn A, B, C, D chứa: KCl, HCl, AgNO3, Na2CO3 biết:
+ Cho mẫu thử trong lọ A vào mẫu thử 3 lọ còn lại đều thấy kết tủa.
+ Mẫu thử trong lọ B chỉ tạo kết tủa với 1 trong 3 mẫu thử còn lại
+ Mẫu thử trong lọ C tạo 1 kết tủa và 1 khí bay ra với 2 trong 3 mẫu thử còn lại.
Xác định các chất trong mỗi lọ ? Giải thích ngắn gọn ?
Câu 4: Hỗn hợp X Có khối lượng 35g gồm 2 muối Na2CO3 và K2CO3. Khi thêm từ từ và khuấy đều 0,8lít dung dịch HCl 0,5M vào dung dịch chứa 2 muối trên thì có 2,24l CO2 thoát ra ở đktc và được dung dịch Y , thêm Ca(OH)2 dư vào dung dịch Y thu được kết tủa A. Tính khối lượng mỗi muối trong X và khối lượng kết tủa A.
Bài làm
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