Question

A student combined two clear, colorless solutions. The student observed that the temperature changed from 25°C (in colorless solutions prior to their mixing) to 22°C when the solutions were combined and white solid particles formed and settled to the bottom of the container. Based on the observations, a conclusion was drawn by the student that a chemical reaction occurred.

What reasoning led to the interpretation of data and conclusion?

Answer 1

d: A change in temperature and white solid particles forming support the conclusion that a chemical reaction occurred.

Step-by-step explanation:

Answer 2

The change in temperature and formation of precipitate led to the conclusion that a reaction has occurred.

Step-by-step explanation:

Here the initial temperatures of the two solutions are 25°c and after mixing them the temperature decreased to 22°c. This indicates that an endothermic reaction has occurred by mixing both solutions.

Endothermic reactions require energy in the form of heat. Thus the products absorb energy from the reactants which makes them cooler. A white substance also formed at the bottom of the test tube.

This suggests that this reaction is an endothermic precipitation reaction. The white solid substance that settled at the bottom of the test tube is the precipitate.