3X molar heat capacity difference, yes. But water is 18 g/mole, and W is about 183 g/mole. So tungsten is about 10x heavier per mole than water. The parent pos

3X molar heat capacity difference, yes. But water is 18 g/mole, and W is about 183 g/mole. So tungsten is about 10x heavier per mole than water. The parent post happened to pick a solid material for a nice round molar mass ratio.