The diagram shows the structural formula of a gas - HSC - SSCE Chemistry - Question 4 - 2010 - Paper 1

To determine the number of isomers of the compound represented by the structural formula, we first identify the molecular formula. Given the structure, the compound is likely to be a type of difluoroalkane, specifically derived from ethane since it contains two carbon atoms (C₂) and four hydrogen atoms (H₄), along with two fluorine atoms (F₂).

Identifying Isomers

1. Structural Isomers: These refer to compounds that have the same molecular formula but differ in the arrangement of atoms. We need to consider how the fluorine atoms can be positioned around the carbon skeleton.

   • Possible configurations include having the fluorine atoms on the same carbon or on different carbon atoms.

2. Geometric Isomers: For compounds with restricted rotation, this is an important consideration; however, in this case, the rotation around the C-C bond isn't restricted, so we focus mainly on structural isomers.

After analyzing the structural possibilities, we find:

• Isomer 1: F on both carbons (CF₃-CH₂F)
• Isomer 2: F on one carbon and H on the other (CF₂H-CHF₂)
• Isomer 3: F on the first carbon and H on both on the second carbon (CFH₂-CH₂F)

Conclusion

Based on these configurations, we determine there are a total of 2 distinct isomers for this compound.