Which gas can be produced when methane is heated in a low oxygen atmosphere?

When methane is heated in a low oxygen atmosphere, it undergoes a chemical reaction known as pyrolysis or cracking. During this process, the methane can break down into smaller hydrocarbons and other chemical species, including acetylene.

Acetylene (C2H2) is a product that can result from the breakdown of methane due to its structure and the conditions provided (low oxygen). The limited availability of oxygen means that complete combustion does not occur, which often leads to the formation of various hydrocarbons rather than carbon dioxide and water, which would be the products of complete combustion.

In contrast, while hydrogen is also a possible byproduct in different conditions, acetylene is specifically formed from the breakdown of hydrocarbons like methane under the constraints of limited oxygen. Carbon dioxide is typically produced in the complete combustion of methane when enough oxygen is present, while ethane can potentially be formed from methane as well, but it’s not the primary product resulting from low oxygen pyrolysis.

Thus, acetylene is the most directly associated product in the context of heating methane in a low oxygen environment, making it the correct answer.