Cân bằng các phương trình sau:
1, \(Cu+H_2SO_4\left(\text{đ}\text{ặc}\right)\rightarrow CuSO_4+H_2S+H_2O\)
2, \(Fe+H_2SO_4\left(\text{đ}\text{ặc}\right)\rightarrow Fe_2\left(SO_4\right)_3+SO_2+H_2O\)
3, \(Fe+H_2SO_4\left(\text{đ}\text{ặc}\right)\rightarrow Fe_2\left(SO_4\right)_3+H_2S+H_2O\)
4, \(Fe+HNO_3\left(\text{đ}\text{ặc}\right)\rightarrow Fe\left(NO_3\right)+NO_2+H_2O\)
5, \(Fe+HNO_3\left(\text{đ}\text{ặc}\right)\rightarrow Fe\left(NO_3\right)_3+N_2O+H_2O\)
6, \(Fe+HNO_3\left(\text{đ}\text{ặc}\right)\rightarrow Fe\left(NO_3\right)_3+N_2+H_2O\)