The evidence supports the possibility that the measuring instruments are calibrated for polyatomic gases, rendering the monomer measurements inaccurate.

The higher calculated molar mass suggests that the gas molecules are associating to form dimers or oligomers under the experimental conditions.

The discrepancy indicates that the gas has decomposed into smaller fragments, leading to an anomalously high mass reading.

An unexpectedly high molar mass directly implies that the gas is undergoing a rapid chemical reaction that increases its molecular weight.