9.
A group of students were asked to identify three white powders. The students used physical and chemical properties to identify
the powders They computed the density of each powder. They checked to see if any dissolved in water. One of the powders did
not dissolve in water and they thought it was comstarch. They knew that cornstarch felt slippery and reacted with lodine. The
students put a few drops of iodine on each white powder. One powder turned black; it was definitely cornstarch. Another powder,
baking soda reacted with vinegar. It fizzed and the test tube got hot.
During the experiment, which of these provided evidence of a physical property of one of the white powders?
A)vinegar fizzed
B) test tube got hot
C) comstarch turned black
D)comstarch felt slippery