Answer:
A
Explanation:
The empirical formula won't always represent a molecule if the molecular formula is not the smallest ratio between elements.
One possible answer could be that a chemical reaction has occurred.
45 cm^3 i think? not sure tbh sorry
The first bond between two atoms is always a sigma bond and the other bonds are always pi bonds and a hybridized orbital cannot be involved in a pi bond. Thus we need to leave one electron (in case of Carbon double bond) to let the Carbon have the second bond as a pi bond.