Chemical Identification—Identifying the Unknown
Today, we examined three white powdery substances and performed experiments to help us identify what each one could be. The three substances were all very common household items- , cornstarch, sugar, and baking soda. We examined which of these substances were soluble in water and in alcohol, which ones reacted with vinegar and which ones turned a color in the presence of iodine. We found that each white powder has its own set of characteristic physical properties and chemical interactions with our test solutions. For example, baking soda reacted vigorously with vinegar (ever tried a homemade volcano? It’s usually baking soda and vinegar that create the bubbling “eruption”), while cornstarch turned a cool blue color when we added iodine to it. We learned that “you can’t judge a book by it’s cover” any more than you can judge what a white powder is by just looking at it. In both cases, experimentation or further analysis is needed to find the true identity of an unknown!
Dr. Sahr and Dr. Kennedy