What physical property is identical for the isomers of C,H12 Organic Compounds:
The correct answer and explanation is :
The physical property that is identical for all isomers of C₅H₁₂ (pentane isomers) is molar mass.
Explanation:
Pentane (C₅H₁₂) has three structural isomers:
- n-Pentane (a straight-chain hydrocarbon)
- Isopentane (also known as 2-methylbutane, a branched-chain hydrocarbon)
- Neopentane (also known as 2,2-dimethylpropane, a highly branched hydrocarbon)
Despite differences in their structures, these isomers share the same molecular formula, meaning they contain the same number of carbon (C) and hydrogen (H) atoms. As a result, their molar mass remains constant at 72.15 g/mol.
Why Molar Mass is Identical?
Molar mass is determined solely by the sum of the atomic masses of all atoms in a molecule. Since all three isomers have the same atoms in the same proportions, their molar mass is identical.
What Physical Properties Change?
While molar mass remains the same, other physical properties such as boiling point, melting point, and density differ due to variations in molecular structure. For example:
- n-Pentane has the highest boiling point (~36°C) due to stronger intermolecular forces.
- Neopentane has the lowest boiling point (~9.5°C) because of its compact, spherical shape, leading to weaker van der Waals forces.
Thus, molar mass is the one fundamental physical property that remains identical across all isomers of C₅H₁₂.
Here’s an image illustrating the structures of pentane isomers:
Here is the scientific illustration of the three structural isomers of C₅H₁₂ (pentane). The image shows the molecular structures of n-pentane, isopentane (2-methylbutane), and neopentane (2,2-dimethylpropane) with clear labeling. Let me know if you need any modifications or further explanations!