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

## Step 1<br />The problem is asking us to identify the procedure that would allow a scientist to observe a chemical property of hydrochloric acid (HCl) solution. A chemical property is a characteristic that is observed during a chemical reaction, where the substance's chemical composition or identity is changed.<br /><br />## Step 2<br />Option A, cooling the HCl solution until it becomes solid and measuring this temperature, is a physical property. This is because it involves a change in the state of matter (from liquid to solid), but the chemical composition of the substance remains the same.<br /><br />## Step 3<br />Option B, adding zinc to the H and observing whether or not bubbles are produced, is a chemical property. This is because the reaction between zinc and hydrochloric acid produces hydrogen gas, which is a chemical change.<br /><br />## Step 4<br />Option C, placing a conductivity probe into a beaker of HCl solution to determine if it conducts electricity, is a physical property is because it involves the ability of the substance to conduct electricity, which is a physical property, not a chemical one.<br /><br />## Step 5<br />Option D, measuring the mass of and volume of a sample of HCl solution to find its density, is a physical property. This is because it involves the mass and volume of the substance, which are physical properties, not chemical ones.