<p>Is HCl a compound or a mixture? I’ve gotten some conflicting responses from a Google search, and I want to know how one would figure this out in the scope of Collegeboard’s thinking. </p>
<p>Thanks in advance!</p>
<p>HCl is a compound.</p>
<p>A mixture is a combination of substances that can be seperated physically, without tampering with the chemical properties of the substances. For example, one could seperate sand and iron by using a magnet to remove the iron, or salt and water by evaporating the water. In doing that, you don’t tamper with the chemical properties of the substances - the water will still react with anything it reacted with before, etc., but there is a physical seperation.</p>
<p>A compound can only be seperated through chemical processes. You can’t seperate HCl based on physical properties, as each of the molecules are identical to each other. You could react HCl with iron to produce H2 and FeCl3, but that’s changing the substance and creating new compounds. Thus, HCl is a compound.</p>
<p>EternalFlame, thank you so much!</p>