Which of the following is not considered an inorganic carbon compound?

Inorganic carbon compounds are typically those that do not contain carbon-hydrogen (C-H) bonds. While carbon dioxide, carbon disulfide, and bicarbonates fall under inorganic carbon compounds due to their lack of C-H bonding and their role in various inorganic processes, methane is classified as an organic compound. This is because methane consists of carbon and hydrogen, specifically containing a C-H bond.

Methane is the simplest alkane and is critical in organic chemistry. Its structure comprises one carbon atom bonded to four hydrogen atoms, which characterizes it as organic. In contrast, the other listed compounds do not have this type of carbon-hydrogen connection. Therefore, methane is fundamentally distinct as an organic molecule, making it the correct choice for the question regarding which compound is not an inorganic carbon compound.