The caveats don't apply here, because you're talking about comparing units of volume to units of volume. So even though the volume of a given mass of water mig

The caveats don't apply here, because you're talking about comparing units of volume to units of volume. So even though the volume of a given mass of water might be temperature dependent because water expands if you heat it, the the volume of a given volume of water will always be exactly equal to that volume of water. Sort of like how a foot is always exactly 12 inches no matter what the weather report says.