Chemical Mixtures: Heterogeneous and Homogeneous and phases or layers: When I make salad for the family gathering, I am making a pretty mixture that includes a spring mix of lettuces, radishes, tomatoes, cucumbers, nuts, and much more. Every salad varies, but they are all mixtures – physical blends of two or many more ingredients or components. Since the ingredients vary throughout, this salad is a heterogeneous mixture.
My salad dressing is a different story though. The ingredients in the olive oil and balsamic vinegar dressing that I make are evenly distributed. So, my balsamic vinaigrette dressing is a homogeneous mixture, or in lab speak, is a homogeneous liquid solution or mixture that has two phases or layers. Vinegar is water and acetic acid and is uniform throughout. The oil is uniform also. When mixed they form a heterogeneous mixture with two phases or layers as the olive oil floats on the vinegar layer until shaken.
Separating mixtures: If I want to separate my oil and vinegar I can though it is not as easy as taking something out of the lovely salad with my clean fingers or a fork. Since the oil floats, I can pour off just the oil, or I can get it so cold that the oil thickens and I can scoop it off the vinegar phase or layer. Frankly, I cannot think of a good reason to do this with vinegar, but I sure can with gravy when I want to harden the grease and remove, lowering my intake of unwanted fat.
Filtering mixtures: This is where my husband takes over in our kitchen. He loves coffee and makes it daily, using coffee grounds and water and the all-important filter. He is working with a heterogeneous mixture of grounds and water. He puts the coffee grounds into the filter, which is in a funnel, pours in the water, brews the coffee, drinks the coffee and adds the filtered grounds to our compost. He has demonstrated filtration as a way to separate mixtures.
Distilling mixtures: Now this was hard for me to find an example of, since I do not brew or distill scotch, beer or the like in my kitchen. I did however discover that I can make my own distilled water at home for my iron, or other uses. On doityourself.com they provide the recipe for distilled water in three easy steps. 1) Put a bowl on top of a rack which is placed in a stock pot of some type. Add water from the kitchen faucet, but keep it below the top of the bowl by about an inch. Tightly cover the pot. 2) Boil the water. Steamy water vapor forms. I want the steam to condense on the inside of the pan lid as small bubbles and drip into the bowl until I have enough there, while not letting the water boil the pot dry. The water in the bowl is distilled water. 3) Cool the pot and bowl till able to handle and then place the distilled water from the bowl in airtight containers for storage. Pretty simple, but can’t imagine me ever doing it; however, I will never look at the bubbles on a lid’s underside the same again! And, there we have distillation of a mixture.
So, either in lab speak or kitchen speak, I have experience with heterogeneous and homogeneous chemical mixtures and their phases or layers and we have a wonderful salad with dressing for dinner. I know how to separate mixtures such as taking the hardened fat off the gravy drippings from the turkey, and my husband uses filtration daily when he makes coffee. I can also make distilled water.
I am a kitchen chemist, in training. Yes! My granddaughter is a lab chemist, in training. Yes!