Which of these observations is an indication that a chemical reaction has occurred?
Sugar crystals form on the sides of a boiling pot of sugar water.
A solid forms when a clear solution is frozen.
Steam forms above boiling water.
A solid forms when two clear solutions are mixed.
1 answer
A solid forms when two clear solutions are mixed. This observation is an indication that a chemical reaction has occurred, as the mixing of the two solutions has caused a chemical change resulting in the formation of a solid.