Question

How did the experiement with boiling water compare with the experiment in which magnesium was added to hydrochloric acid?

Both resulted in gas formation.

Both resulted in temperature change.

Both involved chemical change.

Both involved physical change.

One involved chemical change while the other involved physical change.

Answer 1

One involved a chemical change while the other involved a physical change.

Boiling water is a physical change (liquid to gas — no new substance formed). Adding magnesium to HCl is a chemical change (Mg reacts with HCl to form MgCl2 and hydrogen gas — new substances and heat are produced).