During a lab activity, students prepared two solutions separately at the same temperature. later they mixed the solutions and the temperature dropped. why? a. there was no energy input during the chemical reaction. b. energy was absorbed during the chemical reaction. c. energy was released during the chemical reaction. d. the temperature of the surroundings dropped.

The answer is:

[ C. Energy was absorbed during the chemical reaction.]

When energy is released from the chemical reaction, it is expected that the solution will become warm and that the temperature will increase. But, in this example, the temperature decreased. This is because the energy was not released, but on the contrary, the energy was absorbed. When energy is absorbed, the temperature must decrease.