Final answer:
Heating H₂O does not result in the elimination of any alkanes such as methane, ethane, propane, or butane. The question as posed is missing information or is incorrect.
Step-by-step explanation:
When H₂O is heated for elimination, we are typically discussing a dehydration reaction of an alcohol to form an alkene. The major product of this reaction would be dictated by the Zaitsev's rule, which states that the most substituted alkene will be the major product because it is more stable.
However, since H₂O alone cannot serve as a strong enough acid or base to facilitate such a reaction, the question seems incomplete or incorrect. Therefore, upon heating H₂O alone, no alkane would be eliminated, and so none of the listed products (methane, ethane, propane, butane) would be formed by this process.