Final answer:
The molecular formula for a molecule with the formula C5H12 is C5H12.
Step-by-step explanation:
The molecular formula for a molecule with the formula C5H12 is C5H12. This means that there are 5 carbon atoms and 12 hydrogen atoms in the molecule. To calculate the number of different molecules with this formula, we need to consider the different ways these atoms can be arranged. One way to do this is by using the concept of isomers. Isomers are molecules that have the same molecular formula but different structural arrangements. The number of isomers for a given formula can be calculated using organic chemistry principles and can vary depending on the specific arrangement of the atoms.