Question

how did the experiment 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.

Explanation:

• Boiling water is a physical change (liquid to gas, no new substance).
• Magnesium + hydrochloric acid: \(Mg + 2HCl=MgCl_2 + H_2\uparrow\), a chemical change (new substances formed).
• Boiling water: temperature change (heating to boiling point).
• Magnesium + HCl: exothermic reaction (temperature change).

Answer:

One involved chemical change while the other involved physical change.