Question

1. Which of the following is NOT evidence of a reaction?a. The disappearance of sugar when stirred into hot water.b. The appearance of bubbles when a metal is dropped into acid.c. The change from clear to pink in a flask when to chemicals aremixed.d. The formation of a solid when tow aqueous solutions are mixed.

Answer 1

1) Chemical change. In a chemical change, new substances are formed. We can evidence this by changes in color, odour or formation gases, or solids (precipitate).

The disappearance of sugar is a dissolution of a solid in a liquid. There is NOT a chemical reaction involved.

Option A.