noun
solute
SOL-yoot/ˈsɑːljuːt/
A substance dissolved in another substance to form a solution.
In salt water, salt is the solute and water is the solvent.

Etymology
From solvere, “to dissolve,” the past participle meant “dissolved.” Used as a chemical noun, it names the substance that has undergone dissolving, rather than the medium that dissolves it.
In context
the hot chocolate mix would be the solute overall water is a great example to use when talking about solubility and dissolving substances
More examples
- Sugar acts as a solute when it dissolves in tea.
- This solution contains two solutes: salt and sugar.
- The students measure the mass of the solute before dissolving it.