Có bao nhiêu đồng phân cấu tạo có công thức phân tử C 4 H 9 Cl

Server selection error: context deadline exceeded, current topology: { Type: Unknown, Servers: [{ Addr: 10.0.0.9:27017, Type: Unknown, Last error: connection[] error occured during connection handshake: dial tcp 10.0.0.9:27017: connect: connection refused }, ] }