Which procedure would best allow a scientist to observe a chemical property of hydrochloric acid (HCl) solution?

Question

cooling the HCl solution until it becomes solid, and measuring this temperature
adding zinc to the HCl solution and observing whether or not bubbles are produced
placing a conductivity probe into a beaker of HCl solution to determine if it conducts electricity
measuring the mass of and volume of a sample of HCl solution to find its density

Answer 1

To best observe a chemical property of hydrochloric acid (HCl) solution, the most appropriate procedure would be:

Adding zinc to the HCl solution and observing whether or not bubbles are produced.

This procedure allows the scientist to observe a chemical reaction between the zinc and hydrochloric acid, which produces hydrogen gas (H2) as a byproduct. The production of bubbles indicates that a chemical change is occurring, demonstrating the reactivity of the acid, which is a chemical property.

The other options are more related to physical properties or phase changes rather than chemical properties.