Because oil and vinegar are not miscible. -(you can shake or stir them together, but they soon separate.)
Suspension
vinaigrette
Salad dressing.
It is necessary to shake an oil and vinegar salad dressing before adding it to a salad because they separate easily.
Salad dressing is in the fat category...
eating a dry salad / vinegar
no
No. Salad dressing is a heterogeneous mixture of oil, vinegar, and various other ingredients.
Yes there is
Heterogeneous materials can be separated as they are made from separate components. Oil and vinegar salad dressing is an example of heterogeous product.
If you can see particles (like spices) in it, it's not a solution.If it separates, it's not a solution.Italian dressing has both those properties, so it's not a solution twice over.
Salad dressing is a heterogeneous mixture of oil, vinegar, and various other ingredients.