Just having some problems understanding why one is dependent on pressure and temperature and the other is not. If molarity is moles of solute/litres of solvent, why would this change with pressure and temperature? A litre of water will remain a litre of water at any given temperature and pressure no? If somehow that changes and equating 1 litre of water to be 1 kg of water, wouldn't we be destroying mass? If that were in fact the case, wouldn't the molality be dependent on these factors too then (since 1L = 1 kg)?