Final answer:
Water (H2O) would have unusually high heat capacity due to its hydrogen bonding which leads to stronger intermolecular forces.
Step-by-step explanation:
The molecule that would have unusually high heat capacity is H2O (water).
The heat capacity of a substance is directly related to the amount of energy required to raise its temperature. Water has a high heat capacity due to its hydrogen bonding.
Hydrogen bonding occurs between the hydrogen atom of one water molecule and the oxygen atom of another water molecule. This bonding leads to stronger intermolecular forces and makes it more difficult to heat up or cool down water compared to other molecules.