? I'm not quite a physicist, but I'm pretty sure this is wrong. The closed system under consideration here consists of both the solute (from the parts of the pl

? I'm not quite a physicist, but I'm pretty sure this is wrong. The closed system under consideration here consists of both the solute (from the parts of the plumbing system the water has passed through) and the water. If hotter water dissolves more solute, then less solute remains in those parts. What part of this violates conservation of mass?