To test for protein you would add Biuret(if it changes to purple there is protein is present.
To test for starch you would add Iodine (brown to blue-black means it's present.
To test for simple sugars you would add the chips in a test tube and add Benedict's solution.(if the color changes immediately to blue or orange it is there.
Lastly,to test for fat, put the chips on a brown paper bag and wait for the to evaporate. The grease stain indicates that there is fat present.