Answer:
See explanation
Step-by-step explanation:
In chemistry, the idea of "like dissolves like" is of utmost importance. A substance is only soluble in another with which it can effectively interact.
We must note that to be "soluble" means that the solute actually interacts effectively (dissolves) in the solvent.
However, vinegar is a polar substance while oil is a non polar substance hence the two can not effectively interact. That is, the vinegar can not dissolve in oil.
The two will separate into two phases upon standing. Therefore, the bottle of salad dressing made with oil and vinegar must be shaken in order to mix the two thoroughly before it is used.