Final answer:
In a solubility test of a mixture for liquid-liquid extraction, it is recommended to use excess solvent and the amount of solute can vary depending on the desired concentration and properties of the solute and solvent.
Step-by-step explanation:
In a solubility test of a mixture for liquid-liquid extraction, the amount of solvent and solute used depends on the purpose of the test. Generally, it is recommended to use excess solvent to ensure that the solute fully dissolves. This allows for efficient separation of the desired component from the mixture. The amount of solute used can vary depending on the desired concentration and the properties of the solute and solvent.